All of my fucking yes.
Honestly, this is my 3rd favorite 3D Sonic game(With Colors and Heroes being 1st and 2nd, respectively) but this game is still awesome to play. Releases October 4th on PSN and Oct.5th on 360, with the PC release coming sometime afterward. I don't know what the price is, but assuming Jet Set Radio was released a few weeks back, I'd say 10 for the game and another 5 for the Battle DLC Add-on.
Edit: PS3 release date is October 2, and the Battle DLC add on is three dollars(or 240 MSP)
http://blogs.sega.com/2012/09/17/nights-into-dreams%E2%80%A6-and-sonic-adventure-2-available-in-october/
Also, Nights into DREAMS is coming out on that same day, and that game is getting a holiday expansion that was only available on the original Sega Saturn version.