I think the hope is that the broader Android scripting and JRuby communities will step up to help. There is already a project[0] that allows bridged access to a lot of Android APIs via Python, and Lua. Getting JRuby to this level wouldn't be a huge effort, and would definitely give people a bit of motivation to move forward
That said, I think in the short term it's a pipe-dream. Getting the code going is the easier part, building the development infrastructure around it is a lot harder.
I'd love to write Android apps in Ruby, but I'm not holding my breath.
[0]http://code.google.com/p/android-scripting/