Small enough, in fact, to make it the world's thinnest 1TB hard drive right now. The small frame doesn't mean it skimps on features, though: it has motor shafts at each end to reduce vibration and improve tracking, secure parking to keep the heads away from the plates during shocks, and both electromagnetic and piezo actuators for more precise movement.
For $140 with a two year warranty, it seems like a pretty sweet deal—and should help all those exciting new Haswell ultrabooks stay as slim and slinky as possible. It's available as of today, for both OEMs and consumer alike. More here.