I'd like to see SE5, just the way I want it, with all my suggestions implemented.
Failing that, I'd like to see a wiki-MMPORG: Players live in a community-driven universe rather than a centralised, developper-led one. Open source code and distributed servers (much like the web) would allow the players to build the game universe themselves, and to mod the code or program pug-ins to allow all kinds of wierd and wonderful new items, behaviours and interactions. There would have to be some kind of central governing body to test, rate and approve code mods and maintain some kind of cohesion of the game universe and code, but there would be nothing stopping you stepping away from that body and doing your own thing if you wanted. You just wouldn't get so many visitors if you were left off the 'official' list.
Pretty soon you'd have a a somewhat anarchic Online universe of mind-boggling diversity, stunning sophistication and patchy but acceptable compatibility. (Sound familiar, web Users?) All in full-on, surround sound, seat-of-your-pants fully immersive 3D. Of course, the open-source and decentralised nature of the game would mean things like play balance and cheat-control went almost straight out the window from day one, but if the aim of the game was to create, explore, inform and socialise rather then to run around gaining XP and collecting trinkets, then who cares?