According to the Washington Post, Bullock will tap his lieutenant governor, John Walsh, who is already running for Senate. That would give Walsh a year of incumbency to add to his resume, but it could also make campaigning harder, especially since Walsh is in the midst of a primary battle with his predecessor, ex-Lt. Gov. John Bohlinger. (The winner will face GOP Rep. Steve Daines in November.) And maybe time spent in Washington isn't necessarily a positive on the campaign trail, though presumably Montana Democrats have poll-tested this every which way.
Of course, this is all assuming Baucus' appointment actually goes forward, and that he's confirmed in a timely manner. But in this post-filibuster world, he's probably good to go. That means Montana will soon get a new senator—and China will have to endure the stupid things that come out of Baucus' mouth instead of us.