I work as *nix admin for over a decade now, use gentoo as my sole workstation at work and can't imagine not having linux machine for work but...
... to be honest linux desktop is nowhere near ready to be used as home desktop. Driver support, where exists is amateurish, if not laughable. Driver support, where doesn't exist, becomes a chore and annoyance for someone who's not experienced and very patient. Hardware acceleration is nowhere near Windows levels, scrolling is less smooth, browsing with Opera and Firefox is more ackward than with the same browsers under win (font formatting always an issue somewhere, flash and plugins are still hit and miss, get to badly formatted site and it will be utter mess - Royal Mail website springs to mind - I don't care if it's badly written, it works under windows - so let's not be so stuck up about standards). OpenOffice still feels like workaround than alternative, linux is still missing well designed every day tools, from fully featured WYSIWYG editors, through proper foto editing tools (first one to mention gimp will get slapped with a bit of a trout) to even lighweight, properly working fully featured email client (and no, neither Evolution nor Sylpheed is even close). Yes, it works, yes, it can be made to look pretty, yes you can play around with multiple desktops and fake transparencies but at the end of the day - why would you want to trade overboard gimmicks for what essentially is very functional and nowdays stable home desktop? Living with linux is a bit like getting a bit too far with windows blinds and samurize - looks ok on screenshot, then it just starts to tick you off, because when you don't work in shell or flick between tasks, but want just point and click desktop it's anything but graceful. Linux is slower to do home desktop stuff with, if it's pretty it's bloated and heavy, if it's basic it's just not functional. It was never meant to be point and click and home use is just that. For work use - hell yeah - fluxbox, two days of configuring and it's great. But for home use - OSX - yes. Irix - maybe not these days, but sure, any of linux desktops - not really.