This looks like a side-effect of Gavin's change to allow you to use fully-qualified component names using a "." as a separator instead of "$". All of the seam components are "org.jboss.seam.*". If you override "org", things can blow up.
It might be possible for us to change the seam component naming to "seam.*" but that would only solve the short term problem. So, for now - avoid "org" and any other toplevel namespace components that you are likely to use.