I'd like to bring everyone's attention to ureka (http://ssb.stsci.edu/ureka/) a new binary distribution centered around python, IRAF, and commonly used astronomical image viewing and visualization software (e.g. DS9). They include a large number of python modules, in fact most of yt's source dependencies:
All this software is available for OS X and linux and because it's a binary download it should run significantly quicker than yt's install script.
I'll admit that I haven't tried installing it yet but it might be worthwhile to experiment a bit. If it's a good fit, we could add instructions to the website or the docs or even try to get them to include yt out of the box.