PostGIS 2.0.0 is coming closer to gold and we are on final count down. One small step for you and one giant leap for PostGIS. We are at RC1 right now. We have experimental windows builds for both 32-bit and 64-bit PostgreSQL windows (8.4,9.0,9.1) for those who want to give it a whirl before official release.
Give them a try :Windows PostGIS 2.0.0 rc1 binaries. Join the party.