The new application programming interfaces, or APIs, will let software makers extend the functionality of the Windows kernel in 64-bit versions of Vista
The final versions of the APIs won't be available for a while. Microsoft plans to release those with Windows Vista Service Pack 1, which analyst firm Gartner expects to come in early 2008. Until then, users of security technologies such as host intrusion-prevention systems should postpone buying 64-bit versions of Vista, Gartner has recommended.
http://uk.news.yahoo...vista-apis.html