Hi Phil,
At the current development pace of Haiku, I think their goal, which is a full desktop OS, will be met in less than a year.
Already there's an updated VLC, handbrake, etc., and because the OS is cohersive in all aspects of design, it should take over Linux on the desktop. (At least for me, it already has!)
Already Python 2.6 is in there too!, so most of my daily development is now on Haiku

The speed is awesome, although it's still not fully optimized.
Boot time is about 12 seconds from splash to full desktop, something Linux, Mac or Windows can't do.
Not to mention the BFS is journaled, so you can pull the plug on the machine as many times as you want without data corruption.
The first Alpha release looks more like a BETA release
Only when I want to watch some Flash or weird Codec movies, I'll boot into OSX for that

Which I have to do anyway, say for watching Fox, because the Codec they use (Move Player) only works on Mac and Windows, so Linux is out of the question.
-kwag