Let me know if I miss anything.
I've included seats that aren't really open seats since their current holders will be replace under "resign to run" laws before Nov. 2008. I've included those seats, since the incumbents will likely be weaker than other incumbents who have previously faced the voters. These seats are marked with an asterisk
LD5* (Konopnicki) - Probable
LD9* (Stump) - Running for Corp. Comm.
LD18* (Anderson)? - Assuming he's running in CD5.
LD20* (Robson) - Running for Corp. Comm.
LD22 (Farnsworth) - Might be open early if he is running for AG.
LD25 (Alvarez) - Running for Senate
LD25 (Burns) - Running for Senate
LD30* (McClure) - Running for Corp. Comm.
LD30 (Paton) - Running for Senate
Judging solely by the makeup of these districts, it looks like the important races are in LDs 12, 20, 25, 26, and 30. The other seats look none too likely to switch parties, open seat or no.