I watched both of these being played. Scratch at their E3 party, and DJ Hero at a pre-E3 event. DJ Hero looks way more fun, and it seems like the button placement on the platter makes more sense in the context of gameplay. Watching Scratch being played it looked much more like a GH derivative than something that had the spirit of turntablism (is that a word?).
And I'm not just saying that as a company man. When you see both in action, DJ Hero just makes more sense. Even people who are presdisposed to dislike ATVI (such as my friend at Harmonix, and the dominant video game bloggers) were impressed by what they saw out of DJ Hero at the show.
Also I have approximately 1000% more confidence in Activision being able to deliver a larger volume of licensed music than the nobodies who are doing Scratch.
