In the jboss downloads area, http://labs.jboss.com/projects/download, under tools, it has jboss IDE for eclipse (which the seam 2.0 documentation and earlier refers to). The most recent version there is 2.0.0 Beta2. There is no mention of an eclipse update site (only for the stable 1.6 version)
I only discovered by accident this forum (many screens below the top of the forum list) and that there was a version 2.0.0beta3 and that you were renaming it Jboss tools.
The jboss download site should be updated, I think.
thanks for pointing that one out.