I was reading up on 64 bit and comparsions to 32 bit. This is a few links with some highlights that stuck out. If you have an IIS / 64 bit or 32 bit running on 64 bit story, link, pass it along.
MSCOM
http://blogs.technet.com/mscom/archive/2005/09/26/411568.aspx
Two posts by Thomas Deml
http://blogs.iis.net/forums/rss.aspx?ForumID=1083&PostID=1680123
How to enable 32 bit worker processes
http://support.microsoft.com/default.aspx?scid=kb;en-us;895976
-32-bit processes running under WoW64 get 4Gb of addressable virtual memory.
-kernel memory isn’t sacrificed to squeeze out more VM for usermode processes. (Even with 32bit IIS worker processes, the kernel runs native 64bit.)
Microsoft.com Moves to x64 Version of Windows
http://technet.microsoft.com/en-us/library/bb735208.aspx
Note: IIS version 7.0 will provide a supported method to run both 32-bit and 64-bit worker processes simultaneously on the same server.
x64 resources on www.iis.net
http://search.iis.net/search/iis/techcenter/x64
Pondering Thought 