Yahoo! Blog wrote Expanding Your Web Searches to Include Deep Web Subscription Content discussing its plans to begin providing a search tool for subscription based content. There is a US version at http://search.yahoo.com/subscriptions and a UK version at http://uk.search.yahoo.com/subscriptions.
The Web content providers include; Consumer Reports, Forrester Research, FT.com, the IEEE, the New England Journal of Medicine, TheStreet.com, the Wall Street Journal Online, the ACM, Factiva, LexisNexis, and Thomson Gale.
Forum discussion currently at WebmasterWorld.