This is actually a fairly big shot across the board of other networks vying for players, including Aurora Feint's OpenFeint, Chillingo's Crystal SDK, Scoreloop, and a few other competing services. ngmoco had originally announced that their Plus+ service would be proprietary to the titles that they published, but the inclusion of Freeverse as a partner means they're likely headhunting for quality titles to add to the mix, much like everyone else.
To a certain extent, this is a behind-the-scenes battle -- consumers will likely choose games based on what they want to play, not necessarily on what social network they're hooked into. It's as if Microsoft, instead of having the overarching Xbox Live system, left it up to developers to award and track achievement points. But you have to think that one big player will emerge here, and then it'll be interesting to see what kinds of rewards the devs who connected with that system will reap.