MMO's suck and are highly overated.
Loads of people online in principle should be fun, but gameplay seems inversely preportional to numbers.
Every MMO I have played seems to purely be about doing repedative task X,Y or Z to "level up", in the false impression your achieving anything other then eating your life away. Seriously, generic fantasy, space, whatever...it all seems to come down to just fighting and leveling, fighting and leveling.
Give me smaller online number of people, but more diverse gameplay any day.
20 player 4-Swords, for instance, would ownz way more then any MMO.
Animal Crossing, likewise, would be better if it was a GMO (group multiplayer online).
I have nothing against vaste numbers of people, but developers dont seem to have the resources to do both that AND make diverse, interesting gameplay.
So lets have small scale, more puzzle based online games eh?
(/ok, one exception, if someone made MMO of bomberman, then that would be fun)