Nate Silver's FiveThrityEight moves to the New York Times website.

I'm always skeptical of polls, but I link to Silver's site. He writes:

A casual reading of trends is somewhat unhelpful: Americans are unhappy with the direction of the country and, increasingly, with President Obama. But in contrast to 1994, the Republicans’ favorability ratings are also near all-time lows. Meanwhile, looking at a single statistical indicator does not provide for precision, and some indicators disagree with one another. It is perhaps necessary to dig a bit deeper -- to look at more data, and to do so in a more robust way -- in order to have a truly good handle on how things are most likely to proceed. And even then there can still be a lot of uncertainty in the forecast. FiveThirtyEight and its statistical models are willing to admit what they don’t know.

I don't think the Democrats will lose either the House or Senate.