The JSR will certainly improve JRuby's speed and simplify development, but I don't think it will affect adoption (and actually I'd say JRuby was already on the map, given that it can run Rails and handily beats Ruby 1.8 performance-wise).
JRuby's real problem is that the Ruby community is wary of anything with a J in the name that's sponsored by Sun. Hopefully this will help out with that.