In 2005 there are only two races for Governor in the United States, New Jersey and Virginia.
According to Tradesports.com the Democrats have a 1/13 chance of winning the seat. That's a 93% probability.
Also according to Tradesports.com the Virginia race looks like a toss-up.
You can go here to look at Prof. Larry Sabato's analysis of these races. The GOP currently has a 28-22 advantage over the Democrats in Governorships. If the GOP picks up either Virginia or New Jersey it will increase that margin.