I spent a chunk of the weekend checking out EQ2X, and it occurred to me that I'm suddenly looking at four separate MMO's that don't require a traditional monthly fee. With EQ2 and LOTRO joining DDO and Runes of Magic, it's been two months since my most recent MMO subscription lapsed.
These games aren't entirely free - for all but ROM, I have previously paid money that allows my current/future level of access to the game world. Still, for at least the medium term, I can count on being able to access any or all of these games whenever I want to, without any impact on my current month's budget.
Moreover, it doesn't stop here. We have games like Warhammer and Conan running unlimited free trials, and other "true" free to play games, such as Allods, that I have yet to visit. The folks at Cryptic made an official comment that makes it sound like some form of free play might be coming to STO.
In short, there are a lot of options on the market with low or nonexistent entry barriers, and limited requirements for long-term commitment. This may or may not be a good thing for the games in question, but I'd be even more worried about the next round of MMO's.
You can't really compete on price when so many high quality games are available at these terms. You can't really compete on quantity with games that have been around for 3-6 years. You can try to compete on quality, but A) you have to actually succeed in producing higher quality and B) you still need quantity if you want to keep collecting monthly fees.
How do you compete in this market? Hopefully someone's got an answer to that question, but it looks pretty challenging at the moment.