If they don't get a Wii Version out close to GHIV, a lot of Wii owners are going to choose GHIV. Including me.

GH: WT is going to be better just because of the create-a-song feature. I can imagine actual garage bands making their music on Guitar Hero to build a fanbase, and get their songs heard.

It's genuine innovation. Rock Band will suffer with a delayed Wii and PS3 launch, as they are bigger in america and Europe respectively.

 Online play, rumble for the Guitar, and wireless insturment in addition to more songs with a much cheaper pricetag. Drums and Vocals are nice, but given they removed some of the coolest parts of the game (create a charcter) I will just as easily wait until they put forth the smallest amount of effort towards making the game decently. Now you have the fact that Guitar Hero 3 guitars will translate over to GH4 (which has all the features RB removed and then some) and it is very hard to build a case for not waiting a few months.

You miss one point, which is that GH3 has been out for for sometime and RB is going out now (could have used that time more wisely). Sure I could have bought GH3, but I didn't because I was waiting for RB, after the port debacle I am now waiting for GH4. And living in Europe waiting for these things to jump the Atlantic it changes your perspective. I only wait for the experience I want. The only thing I would miss out would be the drums, since I already use (and have great fun) a freeware software called UltraStar to sing songs I make myself.

Heck, I'm even looking into Ultimate Band and see how that turns out. I sometimes think these music games are too expensive for my wallet.