What changed between the beta 2 and release profiles?
For existing beta 2 profiles, nothing changed. In other words, the “beta 2” suffix was simply dropped from the name of the profile. The release profiles (from November 24, 2008) contain additional profiles for new cameras, coinciding [http://blogs.adobe.com/lightroomjournal/2008/11/camera_raw_52_and_dng_converte.html|with the release of Camera Raw 5.2].