I like Linux, and I think it's ready for 90% of the market.
I've been using Ubuntu and PCLinuxOS for the past two years and have been having a great time with it. PCLinuxOS, imo, works better out of the box (especially since it's not trying to be commercialish, so it has no qualms about including proprietary, copyrighted, or vendor specific software...having Thinkpad utilities installed by default was nice) but Ubuntu's Debian base (and correspondingly apt-get) is better for the average user...ie, it's very easy to find and install new programs.
In fact, I'd say apt-get blows away Windows update and the entire process of installing software on windows. Within seconds, you can search for software keywords, have it installed, and everything on your computer automatically updates.
I've switched over to OpenOffice and Firefox exclusively, even on my Windows machines. When I send people an openoffice document of any complexity however, I save it as a PDF so I know it won't get corrupted. The GIMP is good too, I used Photoshop in the past and could never figure it out just by playing around. I can figure out the GIMP just by playing around with it. In my eyes, those who say the GIMP is harder to use are just used to photoshop first. Best of all, it's free and not nearly the resource hog that photoshop is.
Dreamweaver is sorely missed though.
When Linux works (at least the two distros I mentioned), it just works, and way better than windows for hardware discovery and application support. When it doesn't work...yeah it's not pretty.
Wine is OK, but even its commercial versions don't seem ready for prime time. Interestingly enough though, Wine runs old windows programs better than current versions of windows. Between DOSBOX and Wine, I can play almost all my old PC games better on Linux than on Windows. Support for modern games however is horrible.
I do however keep a virtualized copy of windows 2000 installed to run some windows apps (dev tools and 3d stuff mainly). Actually, on my laptop I find myself running virtualized 2000 more than staying in ubuntu. I like the "sandbox" I get. Plus, I have a compact flash drive as a hard disk in my laptop (32GB) and even with all the tips I found online it still hangs a bit in linux (though not as bad as when windows hangs). However, playing around with windows registry settings I was able to delay writes pretty much indefinitely, making it use only ram until it has to flush. This makes for an incredibly snappy windows installation (with very long pauses when it finally has to flush things).
Ideally, I'd run virtualized linux in windows to get the best of both worlds, except I don't want the performance penalty that comes with using NTFS over native Linux file systems.
Imo, Linux IS ready for the desktop. It just needs someone to start selling it to people, but an approach could easily be made to the market the same way apple markets its computers. (though probably at the low end rather than high)