From pollster Charlie Cook:
With 14 months to go before the 2010 midterm election, something could happen to improve the outlook for Democrats. However, wave elections, more often than not, start just like this: The president’s ratings plummet; his party loses its advantage on the generic congressional ballot test; the intensity of opposition-party voters skyrockets; his own party’s voters become complacent or even depressed; and independent voters move lopsidedly away. These were the early-warning signs of past wave elections. Seeing them now should terrify Democrats.
If there is any possibility of a wave, a good bet would be that nothing of significance will happen in the Senate during those 14 months.