Knowing (more or less) what happened next, Maiacetus looks 'transitionary'. But there is something to be said for trying to imagine it just for what it was: a 'complete' being.
Blog posts occasioned by New Protocetid Whale from the Middle Eocene of Pakistan include (in alphabetical order): Greg Laden, Laelaps, The Loom, New Scientist and Not Exactly Rocket Science. (The Wiki overview of cetacean evolution is also useful.)
P.S. New Scientist has a gallery here.