I've been considering a carbon fork for my steel 2000 Marin San Marino (it was spec'd with a 1" steel threadless fork). Here's one listed on ebay:
http://www.ebay.com/itm/Ritchey-Carb...item336b0dda19
The bike would lose at least a pound. I'm currently running a 1-1/8" stem with a shim, no issues.