I love linux, btw, and know my way around the command prompt fairly well. And, of course, it is my first preference for most server scenarios.
That said, my opinion is that it's a near failure as a desktop OS.
I have Ubuntu installed on my Dell laptop and have had it on there for about a month. It's certainly usable, and I certainly get my work done in it, but it always feels like I'm using something that has been duct taped together. Everytime I climb back aboard my Mac Pro at work, it feels like I just took a shower.
For starters, X has to go the way of Quartz. I still can't get this laptop to play full screen video at a decent frame rate. No problem when I dual boot into Windows. No problem when I had hackintosh installed on this laptop. Why is this so hard? It's not the decoding, it's the drawing.
Basic shit like window ornamentation is always "almost there" and it frustrates me that it isn't "there". It's like the uncanny valley of UI, this linux desktop.
Compviz is cool, but feels cheap and has all kinds of redraw issues.
Most of the free replacements for professional tools feel like they're designed by people with severe visual disabilities. Froo, you are in for a rude awakening thinking you can replace photoshop with Gimp, even Gimp 3.0 is still a long shot away.
Thankfully, I can get my work done in a full screen terminal for most of it, Eclipse for the rest.
That's my opinion after using it for a month. So not ready for prime time.