"The true quality of a community is ... how easily it can adapt to change."

Very true.

"The fact that the plan for 'moving forward' [is] to pull in another framework wholesale, does not bode well for the Rails community."

Very untrue. In fact, very contradictory to what you first said. The fact that the the Rails community is so willing to adapt to the change that is Merb bodes very well for the community as a whole.

+1 for "the Ruby community != the Rails community." That's a statement worth echoing many times over.