IIS 7 Beta is out since the end of june, sorry I mist that one (I was on vacation). From what I could tell it comes with the beta of Longhorn and Vista.
You can find more info about IIS 7 at those locations :
- www.iis.net
- Internet Information Services (IIS) 7.0 (Beta) on Technet
- «IIS continues security push», an eWeek article by Jim Rapoza
