Masters of Dune partially covers this for you.
The bulk of the scenarios are off Dune. Though still connected due to your House having the governorship.
Houses of the Landsraad appears to mainly be non-Dune stuff though and there will be adventures that focus on the wider universe.
Yup, moving off Arrakis has always been the plan.
Masters is the first taste and weāll be introducing the wider Imperium in the next book.
But if you already know the setting you should easily be able to run adventures on other planets with the corebook.
Current position.
Not much new, but the Confirmations have dropped significantly as they have released and I have reduced the hinted based on new info.
Next big reveals will probably be around UK Games Expo (June) &/or Gencon (August).
Released
Dune Corebook (Base, Collectors & Imperial editions)
GM Screen/Toolkit (Screen & GM Tips)
Sand & Dust (Arrakis Sourcebook)
Agents of Dune (Roleplay Campaign Experience AKA Super Starter Set)
4 sets of dice (Arrakis, Spice, Harkonnen & Atreides)
Masters of Dune (Multi-chapter, non-linear campaign book both on and off Arrakis. Follows on from Agents of Dune, but it is not a pre-requisite)
The Great Game: Houses of the Landsraad (House management & expansion book. Expanded rules for the Spacing Guild & 18 Houses detailed. Lots of cool artwork)
Asset Cards (Agent & Architect assets)
Confirmed
Emperorās Court (Politics & High level characters. Renamed from Imperial Court)
Hinted, but no confirmations
Bene Gesserit book (Waiting until after the TV Series)
Meta Currency tokens (Nothing confirmed yet. Possibly poker chips or smaller plastic ones with House symbols. But still at In-House discussion level)
Era Books (New books will cover time periods other than the Imperium Era)
Currently ruled out
Miniatures (Never say never, but not on the cards at the moment. With CMONs board game Kickstarter even less likely)
Skirmish Game (Would require a re-work of license/new license. Unlikely, but again things can change if Modiphius thinks there is a viable market)
Spacing Guild Book (They had a write up in the Great Game so unlikely to get their own book any time soon)
I really liked the house splats in the new Landsraad book, particularly the dewign of the house banners that put a stamp on the heraldric style of the known universe. Thereāre plenty of other houses that could have been included and Iām sure some that were dropped for space/printing reasons, maybe itād be worthwhile publishing a follow-up companion fleshing out more houses? Thereāre a few pdf-only adventures now that have been published that serve the need for content while reducing overheads, perhaps this is a direction that could be followed to flesh out the setting further?
Modiphius is partially tied by their licence with the Herbert Estate.
Everything has to go through them for sign off (same as with Infinity & STA) so they are limited in which Houses they can expound on.
Pretty sure that anything from the Dune Encyclopedia is immediately off limits unless referenced elsewhere, and fan favourite Ordos seems to be similarly out of favour.
There have been chats about setting up a wiki of fan made Houses, but nothing has come of it yet.
Iām really happy with Houses of the Landsraad and Power and Pawns to add to the core gameplay and flesh out the wider āDuniverseā but I am curious if there is any word as what products may be next in the lineup?
Iād love a Dune Tarot deck although have no use for such, unless perhaps there could be rules for how to use the Tarot to craft an adventure or something. Even then it wouldnāt be all that useful to me but would still buy.
There have been a few hints as to what is coming down the line.
Only the meta-currency tokens have been openly discussed, and even those are still at the theoretical stage from what we know.
There are definite plans for a Bene Gesserit book, though that was originally tied to the Sisterhood TV show so they could incorporate anything from there.
With it being delayed indefinitely it is anyones guess as to how that will impact Modiphiusā timeline.
They will have a big presence at UKGamesExpo at the end of May where we normally get some hints as to what is coming.
Iāve got a few suspicions in my little notebook that arent mentioned above, but until I get corroboration they remain guesswork. (And I donāt want Danny chasing me downā¦ 
)
Thatās probably the book I am most excited about, the BG have always been my favourite faction.
I was initially very excited to hear of the planned TV series but that excitement dropped considerably when I learned it was based on the BH/KJA novel, and now with this current debacle over the series will it even make it to the screen?
Well, I guess Iāll have to wait until May to hear what the news may be.
Books about areas of Dune other than Arrakis would be super cool. So I am looking forward to the Great Houses and the Emperorās House books. Bene Gesserit stuff is interesting too, though I plan on allowing men to learn certain traits as well. hehe
One thing I would like is the equivalent of the Shackleton Expanse for Dune. Masters of Dune is basically just Dune (the book) 2.0 and and as I do not care for āfall of the traditional Imperiumā aspect Iām not as enthused on it as I was hoping I would be.
But yeah a completely unique campaign arc that makes use of the vastness of Dune would be super cool.
Masters of Dune might be what you are after in that case, it goes pretty much everywhere 
We have plenty more in the works though.
A couple more nuggets from the latest AMA on Pawns & Power, despite Andy & Rachel being warned by Danny to not let too much out. 
What we did get is that there are 2 more books currently in the works.
One which is almost ready and another which is being written as we speak.
Actual release dates are more complicated. It relies not just on approval from the Herbert Estate, but production availability and also the other lines that Modiphius is running. Lots of [spherical objects] being juggled by lots of people.
Modiphius is planning non-book items for the intervening periods. The meta-currency tokens are one (still nonword on what form these will take though) but it sounds like there are other ancillaries that will be released with only a short notice period.
The current one will be released āreasonably soonā.
Dune Tarot
Dune Tarot
Dune Tarot
There! Iāve said it three times so it must come to pass.
I will be at UKGamesExpo this weekend and Iām taking my little book of Dune secrets.
Iāve got a few questions (including about ancillaries and Dune Tarot) but does anyone have any requests for me to ask while I am there?
Oh god, donāt help him!
See you there! Plenty of the team will be going.
All I know is I would like more stuff that is not Arrakis. Give me other aspects of the universe, including a campaign that does not go to the desert planet.
I care more about the wider universe and its great houses then I do about that single sandy planet.
I would like more stuff that is not Arrakis.
This, very much this. Any planet, place, any person is welcome.
Generally: details. Carthag was great in S&D, the new houses and planet in Landsraad, etc.
Latest update from speaking to Modiphius at UKGamesExpo. Fairly light on Dune this time (more on Cohors Cthulhu), but some interesting bits in there.
Considering the license issues I agree and would be a good idea.
Never let the opportunity for a terrible pun (or 2) go to waste, eh? 
I may have a reputation at my table. Not a good reputation thoughā¦