Prediction Markets : Senate 49-51, House 226-209
Iowa Electronic Market: Republicans lose control of house: 0.770, Republicans maintain senate control: 0.693, Dem House+GOP Senate 0.521
Intrade: HOUSE.GOP.2006 @ 18.3, SENATE.GOP.2006 @ 70.5
WSX: GOP Senate 62.3%, GOP House 31%
NewsFutures: GOP HOUSE 14%
Smartcrowd Index: GOP Senate 72.19, GO House 26.42

I think the market-based predictors tend to lean Republican just due to their nature, but the profit motive should check that a little. The simple crowd-based prediction poling, like Predict06 has a slightly stronger documented scientific basis, and there’s no arbitrage potential which can seriously affect for profit market prices.

The results are pretty similar, though.