I just received my Microsoft Surface Power Cover pre-order from UPS about 30 minutes ago, and I'm typing this on it now. I can confirm it is not backlit. The F1 is now mute, F2 volume down, F3 volume up. It displays as 2 batteries (battery 1 & battery 2) when you click the battery icon in the task bar. It draws from the keyboard battery to keep the Surface at 100%, then depletes the Surface battery. Currently I am showing 100% on battery 1 and 40% on battery 2 (76% total on icon) for 13 hrs 14 mins remaining on balanced power setting with screen set to 75% brightness. It feels and reacts exactly like the Type 2 keyboard I had, but is thicker (I would say just under double the thickness). In comparison, I would say it feels just a little lighter than the actual Surface. So far, I am pleased with it; as the weight, thickness, and lack of backlighting do not bother me; as I wanted more power to make it through the day and then some.
Black Surface Power Cover for a 128 GB Microsoft Surface Pro 2