LG's Android-powered G Watch is waterproof, metallic, and decidedly square.
The internals on the G Watch are still up in the air, although you can be sure it's an ARM-powered device, and Bluetooth will be on-board for smartphone connectivity.
What we do know now: The G Watch is waterproof, features an always-on screen, and it will charge through several connection points found on the underside of the watch body (so no USB port, as far as we can tell). Google Now is a big factor, judging by the limited info we see on the watch face. As for construction, the smartwatch is metal, which might be a shared trait with the coming-soon G3 smartphone.
The G Watch, along with Motorola's circular Android offering, should make the wearable space very interested later this Summer.