I think that the Wii version will sell more than the 360 and PS3 versions. 

Guitar Hero III on Wii is reaching the 360, but 360 owners have the advantage of buying the game alone, and Wii owners need to buy the full bundle. Now that the Guitar Hero install base on the Wii is similar to the 360, it will outsell the 360 and PS3 versions by a big difference because now Wii owners can buy the game alone.

if there is ps2 version then it would sell the most. the ps3 version wont be close to the wii and 360, so i think it will be

1. ps2
2. wii
3. 360
4. ps3

yes i think the wii version will sell the best,since now they all dont have to buy guitars for it

Completely forgot about the PS2 version. Yes, there will be a PS2 version, and the Guitar Hero hardware install base is huge on PS2, so it will sell a lot of software.

I guess you are right: PS2 first, Wii second, 360 third and PS3 in a very distant last place.

who knows maybe the wii version will surprise

i somehow want this spin off of GH to fail, i'll rather wait for GH 4.

We have a 360 and a Wii and will be buying the Wii version (because people we're going to play with have Wiis, and we like the Wii Guitar better than our Xbox 360 Guitar as it's wired).

It's gonna be a close race between Wii and PS2, followed by 360 and then PS3 (not predicting the difference between those two, but I think 360 will sell more).

Question: How much will On Tour sell?

On Tour will be the best selling DS game for that month. Even if Guitar Hero is dissapointing a lot of gamers, Guitar Hero franchises is very popular and mainstream and a very good selling franchise.

Combine that with a nice price, and a gigantic install base = huge sales.

why would anybody buy this? What's next? Guitar Hero Britney Spears Edition? Guitar Hero: One Hit Wonder Edition??

Give me a break.