I honestly don't see F2P as the future for MMO's. Currently it just seems like a back up plan for MMO's that failed to convince consumers into playing their game. What they need to do is bring something new to the table for MMO's. If they do this and do it good I can see a new MMO entering the market bringing in a large chunk of new players and also evening out the entire MMO playerbase with WoW.
But alas, ever since WoW launched no MMO has actually been able to do this.
On another note, I see the GW2 stlye a much better future for MMOs. buy to play with some minor micro transactions seems like a much smarter idea.