SR1630BC is no doubt a very good server machine that uses S5500BC motherboard with Intel Xeon 5500 series processors.
Like you said, there are currently no driver updates for Microsoft Windows XP and as far as I have the future roadmap, I am unable to comment on any recent or upcoming development in that regard. However, what I can advise you is to update servers' BMC, BIOS and FRUSDR (Firmware) before use and then install Windows XP. You may encounter driver issues especially if you are going to create a RAID and Windows 2003 drivers should not work for Windows XP cause the two OS are based on two completely different architectures.
For any further information, feel free to contact us.
Thank you and have a nice day!
Intel Go Green, Save The Environment!