Nate Silver recently noted just how uncertain most midterm election forecasts are. He's expecting the GOP to pick up 50 seats in the House, although the actual outcome, he suggests, could vary by 20 or 30 seats each way.
This seems like a good point to point out that my forecast of 40 GOP pickups (which now seems relatively conservative) had a standard error of 14 seats. Which means that I can state with 95% confidence that the Republicans will pick up between 12 and 68 seats. That's not terribly useful, I know. The best guess is still 40, but there's a large range there. As a professor of mine once noted, when a 5-year old aims a bow and arrow, the most likely place for the arrow to land is at the target, but everyone still runs for cover.
When making forecasts previously, I have sometimes been led astray by late information and by a reliance on my "gut," which seems to have a bias toward my preferred political party. So I'm sticking with my original forecast.