Quick post to say that I've just posted a new version of glMatrix up on the Google Code repository. This is primarily a bug fix release, but I've also squeaked in a few new functions at the suggestions of some users including: mat3.transpose, vec3.lerp, and quat4.slerp.
I know it's been a while since I've updated the library, but frankly I haven't had much motivation to do so lately. I haven't had a chance to do much with WebGL lately (much to my dismay!) and it didn't seem like anyone else was really using the library. A few days back, though, I received word that the awesome tutorials at LearningWebGL.com have been updated to use glMatrix! Needless to say, this provides a bit more motivation for me to keep the libraries up to date!
I'll be paying a bit more attention to items on the library issue page for the next little while, so please direct any bugs you find or feature requests you have over there. Thanks!