Another consideration is that most Wii exclusive titles have been announced within 12 months of being released, while HD console games tend to be announced far further out ... What this could mean is that the Wii could see its exclusive games list for 2009 grow at a rate far faster than the HD consoles.
Now, people may argue that having a lot of games isn't as good as having several good games but there are always going to be unexpected gems and break-out successes that tend to be related to the number of games you have released. I could be wrong but I suspect that a lot of people looked at Guitar Hero as "That bizzare game where you play with a controller that looks like a Toddlers toy and play air guitar to hair metal from the 80's ... Who will want to play that?"
