Sega was showing a playable version of its next-gen Sonic at the Japan Expo, an event happening this weekend in Paris. Here are two videos (X360 version), showcasing the two characters of the game in two different levels. A third video is also on its way, and should please those for who "Sonic" rhymes with "Speed"...
Update : The second video is now online for good this time.
Update 2 : Third video added.