Looking at the VMware vCenter 4.0 Update 1 Release Notes, it appears we may be looking at 64-bit only versions of vCenter Server in the future:
“Future releases of VMware vCenter Server might not support installation on 32-bit Windows operating systems. VMware recommends installing vCenter Server on a 64-bit Windows operating system. If you have VirtualCenter 2.x installed, see the vSphere Upgrade Guide for instructions on installing vCenter Server on a 64-bit operating system and preserving your VirtualCenter database.”
I’m hoping this won’t be a deal breaker for anyone as we should all have 64-bit hardware in the datacenter by now. However, we may be temporarily inconvenienced with Windows Server platform upgrades from 32 to 64-bit.
In the same document, I also noticed verbiage about VMFS-2 support going away in future vSphere releases. If you’re not completely rid of ESX2 and VMFS-2 in your environment by now, I’d start planning on it soon.
As far as the 64-bit comment, that isn’t new to Update 1. That has been there all along in the RTM 4.0 release notes from May 21 as well. Look under the “Installation Notes for This Release” section.