Now I normally hate, really hate commercial radio station pop music fodder, and while I'm sure DJ Hero will contain some less that steller tracks, after seeing the trailer and gameplay videos on their site, the mixes may, just may pull the whole thing off and make it and interesting game. Being a massive industrial/techno fan, I can only hope that add such tracks as downloaded able content, because while it's great to keep it all mainsteam and appeal to more people, maybe introducing them to other styles of club music would help. I don't mean anything like speedcore, but jesus just some well know trance/techno/electronica would be awesome.
At the end of the day, I'm going to buy it regardless, who am I kidding, its a fucking DJ game. With this and the new Scratch: The Ultimate DJ, it'll be interesting to see which one wins out. Though the Scratch trailer certainly doesn't thrill me as much (again with the hiphop).
One thing that made Beatmania so popular was the amount of original tracks for it, and the insane speed and stlye of most of them. Commercial tracks in my rythem games?? hmmm.