Just read an article commenting on the professor who switched one of his labs to Ubuntu Linux; this is something to keep your eye on, as I’m positive within a year if you check back we’ll find the lab has been switched back to proprietary software.
Many times people invoke the principles of free software as a good reason to switch from proprietary solutions, not realizing that paid professionals do indeed take the time to make higher quality, more usable desktop and workstation software. The reputation UNIX gained (and which Linux is now trying to usurp) for utmost reliability and rock solid stability come from the fact that it was developed by giant corporations who paid their programmers a great deal of money.
Having spent years in the open source world of Linux myself, I can say with some authority that most people who equate the usability of the current Linux desktop with MacOS X or Windows do so because they lack a fundamental understanding of what usability really means, and this is chiefly because they’ve spent all their time using Linux to the exclusion of all else for ideological reasons.
This is not to say Linux won’t ever be at the same standard of quality as its proprietary counterparts; but before it can be, its developers and its current user base have to be more objective, open-minded and willing to do the non-glamorous work of fixing bugs instead of introducing new features and improving usability.