What would you like to see in an MMO?
What would make the perfect MMO?

For me, I'd like to see a game that simulates a realistic world with dynamic, player-driven societies and economies. I'd like it to be free, open-ended and non-scripted. The world should be able to hold its own.

I'd also like them to get all that crap off the screen and find ways to make these games immersive.

Characters should lead realistic lives and deaths.

I'd love to play an MMO where you can raep lolis and then kill them.

An unhackable MMO with mature players who can think for themselves. Sadly, that'll never exist.
Oh, and a competent development team that fixes ALL the bugs, and doesn't just write stuff off as not being important enough to fix.
/works in the industry

Too many "MMOs" just seem like single-player RPGs with handy e-penis comparing function built in. I want the massive multiplayer aspect to dominate the game, with cooperation and teamplay a necessity, a player-run economy, and player created content. People who insist on the right to 'solo' should fuck off and play single player games.

You can solo IRL so you should be able to solo in-game, but there should be a penalty for it (and there usually is.)