I personally think Sony has the most damage control. I want info on games for systems I have now, not systems I can't even buy for a year, and PSP doesn't have all that many good games coming out for it (Neither does DS, but it has more than PSP,) and when PSP's novelties wear off, games are what's going to set apart the DS and PSP. Sony needs GAMES to win the handheld war, and DS is doing more delivering in that category now. Granted that may change later, but for now, DS has the upper hand.
Revolution has some great features, I LOVE the ability to download old Nintendo games, and can see using that to tide me over between big releases.
Sony has their usual GTA (All the games in that series since GTA3 are so similar, I consider that the new NES Mega Man series, new levels and weapons, same gameplay, good as it may be,) GT5 (This may be a showstopper if its graphics are as revolutionary as GT4's were,) Devil May Cry 4 (This series is pretty fun, but from what I hear of the american version, I'm importing DMC3,) etc.
Microsoft has a few nice surprises in store that mnight just make me get an XBOX360 (And the backwards compatability is good because I don't have an XBOX,) but 10x what the original sold (In Japan anyway) is still only GC levels and not near enough to win the genenation (I'm going by the weekly MC numbers hers, I don't know what the totals are.)
In conclusion, the downloading feature, and Square Enix warming up to it makes Revolution my early favorite, again like the handheld war, anything can happen and it can change, but I'm just going on what I see now.