Good catch by Leftist Addition, catching ID Gov. perhaps saying too much to Newsweek:
We've now got five Republicans [retiring or resigning], and I guess there's a few more that may make a statement, from what [Senate Minority Leader] Mitch McConnell's told me.
My money is on Alaska's Ted Stevens, what with the FBI digging around his lobbyist-built homes.
Runner up would be Tennessee's Lamar Alexander, who has been long-rumored for the chancellorship at Vanderbilt.
Inhofe (OK), Dole (NC), Cochran (MS), and Roberts (KS) are all in their 70s, though I've seen nothing to suggest they're also on the way out. After that, I don't see many other options. Would Sununu call it quits in New Hampshire rather than lose by 30 points to Shaheen? Might Graham be sick of sniping from his right-flank in South Carolina?
By the way, nearly a quarter of Republicans up for reelection (five of 21) in 2008 have quit. Then note that of the remaining 16 seats (plus one more special election in Wyoming), we have top-tier competitions in New Hampshire, Minnesota, Maine, and Oregon. Of the remaining 12 Republican seats, we have (or likely will have) second-tier competition in Alaska, North Carolina, Kentucky, and Texas. And we have an outside chance, depending on recruitment, of putting Kansas, Georgia, and Oklahoma in play.
Savor that for a moment.
Update: MyDD's Singer has some evidence that Cochran could be one of the next retirements. If so, we'd have a top-tier race in Mississippi with the very popular former Attorney General Michael Moore (not that one) our probable candidate.