Michael McConnell would be an excellent Justice, but I don't think this will happen: The President is, I think, too weak right now to name a second Anglo white male with relatively little judicial experience.
Other options include (alphabetical order):
Judge Samuel Alito, 3rd Circuit (apparently the Pres.'s #2 choice after Ms. Miers, last go-round)
Judge Alice Batchelder, 6th Circuit (U. of Akron Law school grad with lots of experience)
Chief Judge Danny J. Boggs, 6th Circuit (hero of Grutter fame; born in Havana, Cuba, by the way)
Judge Edith Jones, 5th Circuit (instrumental in the recent bankruptcy reform; will her being a Texan now hurt her chances?)
I know the latter three personally, and hereby vouch that all of them are simply excellent jurists.
I had thought about Larry Thompson, as well, and still think he would have been a good choice after Roberts, but I think the President will want to avoid "cronyism" accusations for awhile.