We've been doing exactly this in a university lab eynvironment for the past 7 years or so. We started out using RIS on Windows 2000 Server. And we've since moved to using WDS on Windows 2003 Server in Legacy mode.
Setting up the server to handle network booting was actually easier than creating the scripted/unattended installation of XP. Unattended installations of XP are technically supported by Microsoft, they're just terribly documented. There has been far better documentation produced by communities like MSFN. Ultimately, you should start there if you're looking to do unattended installations of XP period (even if it's not from a PXE server).
All that said, with any Microsoft OS past XP/2003, there are no more scripted installations per-se. Even the default install DVDs are just running a WinPE environment and blasting down a WIM image to the hard drive. However, You can still make a totally customized/scripted installation though using tools like WAIK and MDT. I should also probably mention that PXE based WIM deployments will require running WDS in Mixed or Native mode. Also, I think the WDS included with Windows 2008 Server does not support legacy mode.