I don't know... It seems kind of ridiculous for Apple to charge $70 for the leather smart cover and then release another add on to the case that most likely will cost $40.
This one does too:
http://www.marware.com/ipad-cases-and-covers/ipad-2-cases/microshell-ipad-2-case
I've got one on pre-order. Rumor says they may ship this Fri.