Revisiting XP SP3 on Cablecast

I know this has been brought up before, but I want to re-ask this. Have things changed so that XP SP3 can be installed on Cablecast machines. We have an SX-4 which is the only XP machine in the building without SP3.

All of our machines have Powershell 1.0 for administration. In a few months, Powershell 2.0 will be released for XP and it will almost certainly require SP3. I really want to bring the SX-4 up to the same SP level as the other XP machines, and I need the remote administration capabilities of PowerShell 2, since we will be moving our office PC's to Windows 7 (which includes PowerShell 2) at the end of the year.