For those who have resisted Vista until now, you might want to hold out until
WIndows 7 is released in 18 months or so.
XP is
officially withdrawn from retail sale as of June 30 (not sure when support stops?). It may still be available as an OEM install on new hardware until early 2009.
I'm happy to keep running Linux with the Compiz window manager. Gives me all the graphics bells and whistles I could hope for at a price that's just right
[If I ever get into astrophotography, I may have to rethink this because much as I like Linux, the number of useful astro packages it supports, is limited.]