A lot depends on what incumbents run and which ones don't. The Republicans certainly do have more seats up for grabs, but a lot are in safe states.
PS (to NJ hack): Ted Stevens has already said he's running for re-election. You can mark that seat as safe.
If I am the NJ hack, which I assume I am, Ted Stevens is no safe bet, and his son would do much better if he changes his mind
Ted Stevens is beloved in AK. He wins unless they find him in bed with a dead girl or a live boy, and maybe still then.
You are but one of many NJ hacks that populate this forum. I have chosen to give the lot of you the simple title of "NJ Hack" since it fits everyone so well.