So, I'm buying this as a gift for my father. It would appear that all the peripherals are wired. Is that a correct assumption? I know for sure the Guitar is, but can't tell about the others. How long are the cords?

This is going into a home theater room where the components are in the closet. The Xbox 360 will be there as well.

Yep, they come wired but I believe you can get a wireless guitar now. The wires are about 10' or so. I have mine in my home theater room and truth be told, the wires are messy and annoying; but the game is fun as hell.

Is there any way to extend the length of the cords? Do these plug into a USB port on the machine? Maybe a USB hub?

The 360 version comes with a Hub that requires a separate AC adapter (included). You can use any USB extension cord with that (or any of the controllers).

Ahhhh, awesome. USB extension cords would be fantastic. Thanks for the help!

No prob, that said I'm not positive on this, but you may have to be sure the cords support powered USB. That said, I don't think I've seen one that doesn't.

So the 360 guitar is wired in Rock Band? Did not know that - the PS3 guitar is wireless.

Yes, the guitar is wired when you buy the complete package however as others have said, you can now buy the wireless guitar separately.