What will November 2014 hold? From this far away, no one can really say. But things seem to favor the GOP.
Several states have competitive Senate races where long time Democratic seats may be lost; Montana and our own Michigan come to mind. With an effective 55-45 majority, as the two 'independents' caucus with the Democrats, the Republican opportunity to take the Senate will be an uphill battle. But it is a battle which can be won.
To begin with, Obamacare has been a disaster and Republican candidates will harp on that. They will make their races against the President as much as against their opponent. They will also attack Mr. Obama's obvious attempt to start class warfare as he fans the jealousies brought on by talk such as the income gap. Especially as the President heads into increasingly lame duck status, Republicans will see him as weak. Unless things change dramatically, Obama will be easy to run against.
Then, too, midterm elections historically tend towards the minority party; this is presumably because there is not national elections to offer a coattail effect, or a drag effect, for that matter, where a weak national candidate hurts those farther down the ballot. But it is also because the more serious voters turn out for them, and these gravitate towards the conservative. Right wingers of course tend towards Republicans themselves because of this.
It will be an interesting election year any way you slice it. As a precursor to 2016 when the Presidency is up for grabs, it will be very interesting indeed.