From what I've read, Kyrlion Carbons are a good choice in the rain. The "carbon" in the tread helps wet grip, I guess. Check out the Michelin page on them: "superb grip on wet or dry roads". For wet, Michelin promotes its Pro2 Grip as having 60% better wet grip than the Pro2 Race. Makes me think the Pro2 Race is crummy on wet roads. Also the Pro2 Race Limited Edition is supposed to be thirty or forty % better than the regular Pro2 Race in the wet.
A cheap tire that seems to be made for rain is the IRC Paperlite Aqua - $15 at Nashbar right now.
There is no advantage to tread on a bike tire used on pavement, wet or dry.