Hi Tim,
This did change for 8.5. LabVIEW 8.5 supports Windows Vista, XP, and 2000. If you're curious, I found this information in the "System Requirements" section of the 8.5 Release Notes:
http://digital.ni.com/manuals.nsf/websearch/B28425E23C35BD01862572F2001A5A81
I'm not aware of any exceptions for MathScript, so you should be good to go.
Thanks!
Kate