Well I have made the switch at work to Ubuntu now, using open office etc. I have Ubutuntu on this computer as well, but I don't use it as much as the software I need at home is for XP.
One thing is for certain though....
More supoort for Ubuntu and Vista is in trouble. Ubuntu is really a nice, safe OS to use!
Take a look at this for more MS blues.
http://www.theregister.co.uk/2007/04...aming_oddness/
Dunno if I would make the switch to mac though....