Update: Larry Sabato et al. weigh in along the same lines. "While many races remain close, it's just getting harder and harder to envision a plausible path for the Democrats to retain control of the Senate." They note a "decent chance" that a runoff election in Louisiana or Georgia may actually provide the magic 51st seat, not the election next Tuesday.
In Colorado, the Quinnipiac Poll has Bob Beauprez up by 5% over incumbent Gov. John Hickenlooper. The 538 folks rate Quinnipiac fairly highly at a B+. They also calculate a "house effect" of +1%R, so let's say Beauprez is really up 4%. That is still a shade above the 3.4% confidence interval. See this post for why I'm particularly interested in this one.
Update 2: The Denver Post and Survey USA have the Colorado governor's race a dead heat, with the caveat that this is Colorado's first all-mail-in election, so pollsters really have no $%*&^* idea. Okay, I paraphrased that last part a bit.