Kepler had already lost one of four reaction wheels (critical for pointing) last year, and now a second one has died. It can't accurately point with only two wheels, so unless they can revive the first one that failed, the mission is probably over.
NY Times story
Ball Aerospace photos
of the reaction wheel and other components. Subsequent pages let you see where the reaction wheels are mounted.
Unlike the Hubble, it's not designed to be serviceable and isn't in an orbit we can reach.