Barack Obama will nominate Fmr. Iowa Governor Tom Vilsack (D) for the position of Secretary of Agriculture, in addition to Sen. Ken Salazar (D-CO) as Secretary of the Interior, during a late-morning press conference at the Drake Hotel in Chicago tomorrow.

Jake Tapper at ABC News also has sources confirming the latest picks to him. Vilsack, you’ll recall, briefly ran for President before dropping out and endorsing Clinton before switching to Obama. He marks the fourth former Democratic opponent to be chosen for Obama’s cabinet (Clinton, Biden, Richardson, and now Vilsack).

Who will replace Salazar? Well, Colorado’s governor is a Democrat, so no luck for the GOP there…immediately, anyway. Chris Cillizza says that this could actually good news for weary Republicans and that some GOPers agree.

Gov. Bill Ritter (D) will appoint Salazar’s replacement but that appointed senator will have less than two years to establish himself or herself before standing for election to a full six-year term in 2010…

While Republicans expressed optimism about their chances of competing for Salazar’s seat in two years time, there are two obvious hurdles for the GOP: a thin bench and the possibility that retiring Rep. Tom Tancredo will run for the seat.

He also lists several potential appointees, including Ritter himself. Also in the running? Salazar’s brother who currently inhabits a seat that, if vacated, could cause problems for Congressional Democrats. Looks like the race in 2010 should be interesting.