I have just recently (beginning of january) made the switch from XP to Ubuntu, and are becomming more and more happy with my choice!
The only hick-up in my switch was the fact that my wireless NIC wasn't compatible with linux, but a cheap usb wifi-adapter did the trick.
The work related things you mentioned are very well supported in Ubuntu (open office) and for almost all the other software there is a linux equivalent (sites like
Osalt helped me out greatly in these cases).