Joe Schwarz doesn't stand a chance at winning the GOP nomination again in MI-07. He only won it in 2004 because the conservatives were split among three candidates. It will be interesting to see if the Dems can knock off Walberg in 2008, though, in which case Schwarz might able to make a comeback in 2010.
Supposedly Schwarz is considering running as a Dem. Personally I'd prefer to see a bonafide Dem like state-rep. Dudley or ex-state-Rep. Doug Spade (who I believe is blind) from Lenawee county run against Walberg. Either one of them would have a very good chance.