Kristin at E!Online got a sneak peak at the top 20. Amongst other things, she says Wade Robson will choreograph the top 20 group routine, and this:
According to lyrical-contemporary cutie Marquis Cunningham, "They have forewarned us that there's going to be several new genres in the hat that they haven't shown the past three seasons."
Daemon's TV has pics and mini-bios of the most of the top 20. The fact that this info is still not on the show's site, and that Fox can't be bothered to provide it to sites devoted to the show, tells me that they still don't "get" what the web is about.
Shane Sparks will choreograph an upcoming movie with Chris Brown and TI.