Here's hoping for a return to ME1's darker Sci-Fi tone (like a dirty 80's sci fi) and RP heavy mode, or even ME2's compromise between RPG and Shooter elements.
I suspect that is not going to happen, but a man can hope right?
Man, I am still butthurt about ME3's ending. Shouldn't I have let go of it by now?
I sincerely doubt it, hoping for it, but doubt it.
The ME universe was conceived/created by someone else; Drew Karpyshyn (Kotor, Baldurs, Neverwinter, ME1 and ME2 etc.). Heck, Walters wasn't even in on the first game at all, he co-wrote the second, with Karpyshyn still leading the go of things... and the transition/shift in style and theme from ME1 to ME3 kinda shows with the middle ground of both writers affecting the 2nd instalment - who wanted it to go in what directions.
1: Very mysterious, lovecraftian, explorative, unity through diversity, a very lonesome galaxy full of wonders (open but barren), heavily focused on dialogue and talking to progress, good and deep (and time consuming) companion talk about (un)important stuff.
2: Kinda mysterious, less explorative, unity through diversity, improved combat, still heavy focus on dialogue but a little bit limited due to the explorative aspect shortened down, improved companion talk with some more severe choice affecting personal missions etc.
3: Mystery mostly gone (Star Child included...), unity through diversity but Shepard is now doing amazing things solo, further improved combat, dialogue semi-auto chosen which gives Shepard a specific character pre-set, less overall interaction with your squad mates (can't talk to them about a specific event more than once)*
*Although with the whole loyalty mission thing, I can to some extend forgive them for no more side missions - I mean... they already trust you deeply. But they still could've done something more with it, as Walters even somewhat admits here. Indoctrination affection perhaps? Faith/Loyalty vs falling to indoctrination affection/despair?
**Also these points are done minus the extended cut ending and all the DLC to expand on the game: just lining up the initial vision of each released product. It does not make sense to include something that was forged due to feedback unless it is a sequel, if holding it up to predecessors and successors.
...So yeah, sadly, I sincerely doubt Walters is gonna let it go in that direction, he seemed to have his own ideas/visions on how the ME universe should be shaped, and it is in his hands mostly at this point since Karpyshyn left.
Its a matter of creator and keeper of legacys really, and everyone wants to set their own personal mark on something. Walters has the reigns right now, so if you like his work on ME2 and ME3, then that's the direction things are most likely to go (if based on previous work). Not ME1, which saddens me personally, since an intellectual threat is far more menacing than a physically powerful threat. But that's personal taste at the end of the day. They each had their own ideas, and this is the one that ended up being the end lore, regardless of how ME1 set out to do things.
Also sorry for the wall of text. The ending aside, ME3 is a pretty interesting to study really, in many aspects to be quite honest, about cause and effect of things.