You can if you want to - to get them you goto the downloads page, and download the beta.zip. Then you run the install/update.php. Everytime there's a new build, a new post goes in that forum, and the beta.zip is updated.
Usually things are stable, but if there's a bug I always get a few emails almost immediately, so it's fixed right away almost. So you can update as often as you'd like. Right now, things are going to be pretty stable, since I'm planning on a new release, I've stopped any major new features or updates, just bug fixes.