This just in: Ubisoft plans to release a PC-based version of RockSmith some time this coming Spring (March 2012)!
This would tie in nicely with my Internet TV plans since I was leaning toward hooking a PC up to my TV for that purpose.
This news does not, however, necessarily rule out the possibility of an XBox finding its way into my house. (In fact, don't tell my kids, but there may already be an XBox hiding somewhere in my bedroom as we speak. Just in case.) XBox-es also serve as wireless Internet TV streamers, so rather than upgrading an old PC for this purpose or purchasing a separate box it may make more sense to just go with an XBox. I'm prepared for that possibility.
I have learned one thing in my research on gaming consoles: PS3s will play Blu-Ray disks. XBoxes will not. Yet. Makes little to no difference to me as I will not be replacing our rather significant collection of DVDs (including complete boxed sets of M*A*S*H, Friends, and I Love Lucy) with Blu-Ray disks. Ever. For one thing, I don't think our TV is really good enough that the difference in quality between a DVD and a Blu-Ray would be noticed. It would be like playing CDs through the amp and speaker on my old portable record player. For another, if I was in the market for a Blu-Ray player, I'd just buy a Blu-Ray player. They can be had for under $100 on sale. The cheapest PS3 I've seen was easily twice that amount plus some change. You don't buy a game console to watch Blu-Rays. You buy a game console to play games.
Anyway, even if I go with the XBox, being able to play RockSmith on a PC could still be a very good thing. You can't run recording software on a game console. Nor composing software. Etc. Many studios have a PC in them but not a game console. Mine, for example. And, it would be much easier to run RockSmith on the computer I already have in there than to move the XBox into the music room every time I feel like playing in there.
I also popped into an Apple Store this past weekend with my family - at my kids' behest. Yes, yes. They're very nice. But, still grossly overpriced. I checked out Garage Band on a Mac desktop system and watched part of a computer-based lesson by Rush guitarist Alex Leifson which showed users how to play the guitar part to Tom Sawyer. While it was sort of cool to get this info straight from the horse's mouth, so to speak, it didn't hold a candle to what you do with RockSmith. And, notably, RockSmith is not scheduled to be released for Macs (although I suppose it might be possible that you could run the software on a Mac).