Is there any plugin for After Effects to create a 'kinetic typography' video?
As of 2011, there aren't plugins that assemble a typography video for you, because this kind of work is really a sub-topic of motion graphics.  There are tools that can help you with camera animation and rigging in AE though.

My favorite is Video Copilot's Sure Target 2, which lets you think about the animation in terms of what you're looking at, instead of thinking about it in terms of camera perspective.  This makes the work feel similar to using something like Cinema4D's target camera.

Another noteworthy tutorial: http://ae.tutsplus.com/tutorials/motion-graphics/design-rhythmic-motion-typography-in-after-effects/


  If not, then is there any other easy way to do this?


Not really.  Watch lots of videos, take notes on ideas you like, steal the best, and trust in what is difficult.