Rep. Kenny Hulshof and Rep. Roy Blunt have been mentioned as possible GOP replacements, but conservatives shouldn't overlook the possiblity of running former Senator Jim Talent.
... In other news, I am hearing rumors coming out of Ohio that Senator Voinovich is seriously considering making an announcement next week that he won't be running for re-election. According to my sources, Rob Portman would likely be the Republican to replace him. This also opens up the GOP gubernatorial nomination for former Republican Congressman John Kasich.