I traded in my wii guitar and wii version of GH3 for the 360's (since I have one now) for a difference of about 8 dollars. I can't believe how totally worth it the dlc is. I've only picked up the free stuff (halo song, we three kings, top gun song) and the dragonforce and muse packs so far, but it's so nice to get new stuff for only like 5 dollars. Some of them are actually challenging also.
Can't wait for world tour.