Hmmmm....
Open Office...Check
Firefox...Check
Thunderbird...Check
Linux...Comming soon
"Linux...Comming soon"
Linux isn't ready for prime time.
It's a decent server, but as a desktop... it's still lacking. It's pretty darn impressive for freeware, but still lacking. And each "distro", (distribution), has it's own quirks. Gnome vs. KDE as the gui, installer issues, hardware drivers.
Linux is fun, and if you have a small business network with no need to be interoperable with other businesses, it's a legitimate choice.
But, if you have it, and want to work from home over the cisco vpn... ooops. If you have issues and your office supports windows, oooops. If you want to run Civ4 to play in your spare time, oooops. You get the idea.
Microsoft is still the big dog, and will be for the next couple years, at least.