A few intrepid Sonic lovers from the Sonic Stadium forums have come across what appears to be a leaked, temporary box art images for two upcoming Sega titles starring Sonic the Hedgehog. The first image looks like it is the logo for the recently teased Sonic anniversary title, featuring both a modern (thin, green-eyed) Sonic and a the classic-era (spare tire) Hedgehog hero.

Sonic's new adventure is supposedly titled Sonic Generations, which fits in with recently discovered domain name registrations by Sega [via Joystiq].

The second, allegedly leaked box art promotes the third game in the Mario & Sonic Olympic games series. This time, Mario and Sonic will venture off to jolly-old London, for the 2012 Summer games.

Shacknews has contacted Sega for a comment on the two images, but has not heard back at the time of publishing.