I'm holding out for Dreamcast games, since it's one of the few Sega systems I didn't own (and at one point I did own the Master System, Genesis, Sega CD, Game Gear, Nomad, Saturn) and there are games for the DC I would really like to play. Too bad Sega can't/won't get their third-party licensees to release stuff through this program.
Cool! I just went and looked at WP's list of Dreamcast games[0] and honestly, besides Ecco, Seaman and Shenmue there's nothing from Sega I want to play. I'm hoping they do as good a job at bringing third-parties along for the ride as the JP PSN did for PS1 games.