I've read heaps of times people wanting a 'choice' of commentators, which is one of the more ridiculous ideas I've heard, but I'm happy with Vossy, sure, in the future it'd be great to have Sterlo or Fatty doing commentary with him, but that's just icing on the cake. Rabs, well, you can imagine that someone as old and allegedly grumpy as Rabbits would have a hard time spending hours upon hours in a studio recording lines, he probably hated it when he worked on ARL and didn't want to do it again. Fair enough, you can't blame the guy for turning the gig down, he's still a champion, but its a shame he didn't want to do it.
Vossy has done a good job from all reports so far though, and probably has a more suited commentary style to a video game, Rabs gets excited and comes up with off the cuff remarks to make a game exciting, where Vossy is more a traditional style, just calling the action and adding a few 'superlatives' when something big happens.