Sonic CD was a classic Sonic game, ask any forum user or youtube commentor that has ever displayed a dislike for the last decade of SEGA's biggest franchise. They'll grunt angrily and say "Why can't SEGA just make a load of Sonic CD clones, that's what the series needs!"
Not everybody had a chance to play the game originally though and it has seen precious few re-releases in the time since, meaning that for newer, less diehard fans of the series, the release of Sonic CD to 360, PS3 and mobile devices is something of a big deal. They finally get to see what all the fuss was about.
With no exact date set in place just yet, you can expect to be downloading this title over the next two months or so. And, as the trailer says, you'll finally be able to understand the cryptic story of Sonic 4 Episode 1.