I run Fedora XFCE right now on my laptop. I integrate pretty seamlessly into my work's Windows network. The only time I need my desktop Windows machine is when I have to use The one application that runs on Lotus Notes.
E-mail, Vmware, browsing, IM (tool we use to communicate between departments), everything--all runs fine on Fedora.
Heck I even run a game on Steam, and several on Wine.
I do like being able to tailor the distro to the requirement, and leave out lots of overhead.
/johnny
Lotus Notes is evil-ware.