It's not readily apparent at first but this trailer for the upcoming Sonic CD rerelease confirms support for widescreen TVs and monitors. You'll be able to see more of the stage so you can better prepare for upcoming hazards much sooner.
As previously reported, this rerelease features the soundtrack from the Japanese version of Sonic CD. The music you heard from the trailer features a sample from Quartz Quadrant's Present period.
Sonic CD will be released this holiday for Xbox 360, PS3, PC, and mobile devices.