We got a little bit more info on the up coming Sonic and Mega Man crossover from an Archie Panel at New York Comic Con. Not much more but a little. The creators still promise it will be epic and include as many characters from each universe as possible. Also they discussed some up coming stuff in both Mega Man and the Sonic books. Check out the article over at CBR.
Also I found this little Sonic/Mega Man gem on Deviant Art. The guy's name is Lamar Wells, goes by the DA handle of trunks24. He's got a lot of really good Sonic stuff on there, if your a fan like me you should check out his page.