WiC is a great game. But their community is in a state of flux seeing that they had been dropped by Activision and the Xpack indefinetely put on hold. While I'm quite certain they will find a publisher, the community has been lagging ever since. WiC beeing a very online multiplayer focused game, i think community is a very big factor. I'm speaking as a former WiC player myself. I sold my copy.
RA3 while not out looks like it will have quite a big community. Where I'm at, it seems it got a lot of pre orders and there is even a launch event threwn by EA. Big question is how long will the community last.