Nintendo did this with the Gamecube too if you may remember. As soon as the Wii was released, the Gamecube did not see any more releases. Literally.
Also, I'm reading that Danica Patrick will be playable in Sonc & All-Stars Racing Transformed... likely representing Daytona USA (probably meaning The King of Speed and Three Seven Speedway [or a reasonable facsimile] are pretty much locks for the game). As far as Danica, I haven't seen confirmation from CBS Sports, FOX Sports, or even ESPN at this point, but this is too big news to go unreported if correct. I'll post a link once I see one.