Hopefull all of you are moving rapidly to Windows Server 2008, but for the few people who have not finished updating their environment, this might help.
On servers running 2008 or 2008 R2 all of the architectures of systems being imaged was detected correctly and the x64 boot image was loaded and there was harmony in deploment land.
On servers running 2003 R2 some system would refuse to load the boot image. After a little research it seems that this option is passed through DHCP options, but isn’t always reliable, as in my case.
On the 2003 R2 WDS server run:
wdsutil /set-server /architecturediscovery:yes
sc stop wdsserver
sc start wdsserver
Viola! WDS will now confirm the system architecture itself. This makes the boot process a tad longer and creates a little bit more network traffic, but in my opinion it was negligible.