Earlier I noted the crazy good map we have this year. Believe it or not, it gets even better in 2010.
First of all, we have no threatened Democrats --
Arkansas: Blanche Lincoln
California: Barbara Boxer
Colorado: Ken Salazar
Connecticut: Chris Dodd
Hawaii: Daniel Inouye
Illinois: Barack Obama
Indiana: Evan Bayh
Maryland: Barbara Mikulski
Nevada: Harry Reid
North Dakota: Byron Dorgan
Oregon: Ron Wyden
Vermont: Patrick Leahy
Washington: Patty Murray
Wisconsin: Russ Feingold
That's a whole lot of Blue territory, and North Dakota is Dorgan country, while Bayh will be senator as long as he wants to be. Lincoln in Arkansas? That could be a problem if Huckabee runs for the seat, but that's not currently likely.
As for Republicans? It's ugly for them. Alaska, Georgia, Idaho, South Carolina, South Dakota and Utah are initially off the table. But beyond that:
Arizona
John McCain was already vulnerable to a challenge by Democratic Gov. Janet Napolitano. Once he loses his White House bid, does he stick around the Senate? Either way, if Napolitano can be enticed into making a race of it (and it's not her favorite thought), this becomes a top-tier pickup opportunity.
Alabama
The Senate Republicans got lucky when Ag Commissioner Ron Sparks passed on this year's Senate race. They may get lucky again if he decides to run for governor in 2010 rather than take on Richard Shelby. Democratic Rep. Artur Davis is also eyeing the Senate or governor's race, so either way, chances are good we'll have a top-tier Democrat to go after the then-76-year-old Republican incumbent.
Florida
There's no recent polling on freshman incumbent Mel Martinez, but when SUSA was polling 50 states in 2007, Martinez consistently polled among the worst senators in the nation.
Iowa
If incumbent Republican Chuck Grassley runs for reelection, then challenging him would be a tough slog. He remains popular in the state. But he'll be 77 in 2010, making him a candidate for retirement. And really, how many Republicans will want to stick with their rump caucus in Congress? At the rate we're going, there won't be much of a GOP left in 2010.
Kansas:
Incumbent Pat Roberts Sam Brownback has already announced his retirement. If popular Gov. Kathleen Sebelius isn't Obama's vice president, expect her to be a top-tier challenger for this open seat.
Kentucky
Literally senile Republican Jim Bunning came within a hair of losing his race in 2002, and should be retiring after his current term. If he doesn't, Rep. Ben Chandler makes easy work of him. If he does, Chandler makes easy work of whoever fights to replace him. Chandler, who was the second candidate ever adopted by the netroots (back in 2004), would've been a star candidate this year, but decided to wait the extra two years for the sure thing in '10.
Louisiana
David Vitter will face the voters. Once considered safe, his dalliances with prostitutes and the renewed feistiness of his state's Democratic Party threaten to make a race out of this seat.
Missouri
Democrats are resurgent in the state, having taking a Senate seat in 2006, and poised to take the governor's mansion in 2008. Incumbent Kit Bond will sport a huge target on his back.
New Hampshire
Granite State Democrats will complete their top-to-bottom takeover of the state in 2010, ousting Sen. Judd Gregg. Expect Rep. Paul Hodes to do the honors.
North Carolina
Freshman incumbent Richard Burr holds a funny seat -- no one holds it for more than a single six-year term. Before Burr, it was Edwards, preceded by Lauch Faircloth for one term, preceded by Terry Sanford for one term, preceded by Jim Broyhill, briefly appointed to the seat to close out the single term of John Porter East who killed himself at the end of his single term, who was preceded by Robert Burren Morgan for a term, who was finally preceded by someone who held the seat for more than a term, three-term senator Sam Ervin.
Democrats will target this seat heavily.
Ohio
Watch, incumbent Sen. John George Voinovich will be taken out by Rep. Tim Ryan.
Oklahoma
Wacky freshman incumbent Tom Coburn would be vulnerable in any other state, but Oklahoma is tough. Yet he won't have the advantage of running in a presidential year, and he'd be vulnerable to a rematch from his previous opponent, Brad Carson, or the state's other prominent Brad, popular Gov. Brad Henry.
Pennsylvania
Incumbent Arlen Specter has vowed to run for reelection, but he will be 80 in 2010 and is battling a resurgence of his cancer. The state appears to be trending Bluer and there are no shortage of exciting new Dems to take on the race (Patrick Murphy? Joe Sestak?).
A Lieberman-proof filibuster proof majority is well within reach by 2010. The maps of '12 and '14 will be much tougher, as we fight to hold on to our gains from last cycle and this one. But for now, savor the mauling we are in the process of delivering in the middle of his heavenly six-year stretch between the 2006 and 2010 cycles. It's an epic beat down, and it'll continue straight into the end of the decade.
Update: As mentioned in the comments, retirements are possible in Maryland and Hawaii. Maryland would likely be a relatively easy hold, but Hawaii has a popular Republican governor that could potentially make Hawaii a tough hold.