Disclaimer: We still have a long way to go. This prediction expires August 15th.
But I'd say the GOP's chance at taking back the Senate is 50/50, and for holding onto the House it's about 75/25. I've been impressed with the Dem Senator fundraising, but unimpressed with their performance in the polls. They've simply got more incumbents on life support (to borrow a phrase from Sen. Frist, I think) than the GOP does. I think the GOP benefits from three things: redistricting bought them a couple of seats, redistricting also protected all but a handful (relatively speaking) of seats, and the GOP does and will have more money to spend. (I could see the GOP losing House seats, but not losing control of the House.)
There. Aren't you impressed with my highly scientific predictions?
Since the GOP has only a 7 seat pad, your precision is impressive.