"The Dreamcast fans are very devoted," he said. "You see on eBay people are still buying the games and system. We actually have a Dreamcast collection coming out soon. We are looking to bring some of the old Dreamcast games to market digitally and packaged. The titles are still to be announced. The Ultimate Genesis Collection did huge numbers on PS3 and 360, so it's an important part of our business. We've already been releasing some Dreamcast games digitally; Crazy Taxi [for one]."
Quoted from Alan Pritchard, vice president of sales and marketing at Sega during an interview in the latest issue of Game Informer. This means that pre-order on GameStop is real, though wherever the price and release date were real is yet to be known.
Most likely it will at least contain Sonic Adventure, Crazy Taxi, Sega Bass Fishing and Space Channel 5 Part 2, but will that be all or will there be more? Well Sega did say they plan to release more than those 4 in the future so we might start seeing announcement of further downloadable titles in the near future that could also be on the collection.
Some games might have issues getting ported, mainly due to licensing issues which led to the changes in the re-release of Crazy Taxi. Jet Set Radio for example might run into some issues that would led to cut music. Also Daytona USA 2001 would be stuck due to Sega not owning the Daytona license anymore (which is why the arcade re-release of the original Daytona is called Sega Racing Classic).
Also I doubt there will be any online play with any of these releases so that rules Phantasy Star Online out unless they really want to surprise and impress us. Space Channel 5 Part 1 was probably skipped due to the game using pre-rendered video backgrounds that would require a lot of work to look good on a HD resolution. Of course third party games will be out of the question too.
There are still plenty of easily portable games however: Skies of Arcadia, Dynamite Cop, Virtua Fighter 3tb, Zombie Revenge, House of the Dead 2, Outtrigger, Puyo Puyo Fever, Virtual On 2 (already on XBLA), Sonic Adventure 2, 18 Wheeler and many more.