Guys there is an opportunity for you to ensure that Confluence can run as a service on 64 bit Windows. All you need to do is distribute the 64 bit versions of the Tomcat binaries which can be downloaded from Apache SVN repository (this link is for the binaries that are to be distributed with the Tomcat version for 2.10 RC1).
The procedure is simple - have a read of the comment I made in JRA-12965. I have been running 2.9.2 on 64 bit Windows Server 2003 for several weeks now without issue and of course the beauty of this is that I have been able to allocate a significant amount of memory to the JVM (viz. 512m of PermGen memory and 4G for the heap - considering of course that I have 8GB of physical memory installed). Of course I am successfully running 2.10 on a 64 bit Windows Server 2008 staging box.