The first, entitled the Legendary Cars Pack, will feature four new cars, including the Jansen 88 Special, the Cavalry Bootlegger, the Manhattan Spirit, and the GT Nighthawk. Though exact pricing has not been announced, the pack will be sold similar to Rock Band tracks; each car can be purchased individually if you are partial to just a particular one or two, or all four can be purchased together in a pack for a slightly discounted price.
The next pack, the Party Pack, will feature a set of challenges meant for players in the same room; thats right some local multiplayer, over the standard online play. The Party Pack is set to feature another extra set of achievements as well, so mark that date.
I definitely have to pick this game up; with this much content and a cheaper price, its certainly making it onto my Christmas List, if nothing else.