Acutally, thinking of the last two big updates: Powerplay and CQC, both are adding a separate game in a different genre (Powerplay is a TBS and CQC is like arcade space shooter). So, speculating of what one more separate genre they can add, that would be ... text adventure (aka interactive fiction)!
Now you ask: what the hell?
But have you ever heard of the game called Space Rangers? It's like Elite in 2D and it incorporates a number of differend game genres. I suppose it's not well-known outside ex-USSR, as most of its specific humor is probably lost in translation, but here in Russia it was a hit just like Elite in its time. I believe you can actually find the latest fo the game on Steam (though people say the balance was ruined in the later versions).
So, the space battles were turn-based RPG (in 2D), the trading was apparently taken directly from Elite, also there were battles inside wormholes that were like 2D arcade space shooter, there were also ground battles that were 3D RTS + with an option of taking direct control over one unit which turns it into FPS (I think land battles were introdued in Space Rangers 2, but the latest version that is now in Steam should have them), but for me personaly my facourite part of the game were adventures in form of interactive fiction. The thing is you don't need a crowd of coders or artists to make them. It does depend on good writers though. But as long as the writing is good they are so much fun! The tric is it can have ANYTHING without introducing any new game mechanics. Walking around on planets? You only need a writer do decribe the scenery. Shooting things? Just insert some dice rolls. Stealth sneaking into the heart of enemy base to steal their secret plans? As much as you like! Or maybe you should actually create a band to sing songs for your beloved Princess? Of course, why not! Or solve a riddle of an ancient artifact? I hear cheers from explorers here. The best thing? It perfectly fits the Elite: Dangerous with its lots of text taking place of content. So why not turn it into a feature! Interactive fiction can be not less fun that shooting stuff in first person. In fact, fun of shooting stuff is limited by the game mechanics. Fun of interactive fiction is not.
Okay, it's not like they'll actually do that. But let me at least hope for something actually fun.