I have downloaded and installed the latest Hudson version: 3.0.1. The link was provided in my old 2.2.0 instance. After login to Hudson at the right hand side below the bottom bar I can see "Hudson: 3.0.1-b2" link. Most of the core jars in WAR file are also in b2 version e.g
I had the same reaction to the numbering scheme - looks like a beta build! - but regrettably missed the community meeting where it was decided. The -b2 portion is intended to mean "build 2". It is, indeed, the released version of 3.0.1, not a beta. Sorry for the confusion.