You'll probably have to project that idea out to 2015/2016 at least. WoW has plenty of steam to get through another expansion without it and even then they don't need to take the whole game F2P. Let's imagine that the next expansion really is 10 levels. So it's out for a year and Blizzard announces that 1-90 will be F2P with the subscription model in place as is for 91-100. That might change a lot of minds that are adamantly putting a stick in the ground about quitting if the game goes to another revenue model. And F2P for 1-90 at that point would very likely be a hell of a thing for Blizzard and their store.
And who knows where ESO will be by that time. I don't know about anyone else but while I level alts like a lot of other people, I'm really spending my $15 a month for 85-90.