I didn't have a problem upgrading a test site to 3.3-beta1-18972 but 3.3 beta 2 has been released and the plugin will not update to it. Set on "bleeding edge nightlies", updating using the plugin always updates to "3.3-beta1-18972" not "3.3 beta 2". No error is thrown, it just states the usual update text ending with: "WordPress updated successfully".
I've been using Bluehost for over 6 years now and the test site is a standard WordPress setup, no customizations. The WordPress Beta Tester plugin has been working without a problem until now.