Just got my ASUS sleeve - a quick review
Bottom line: I like it. I have a Xoom hard clamshell case and, although it protects the device, it's almost "too hard". This ASUS sleeve is exactly that -- a sleeve. It's light and does what I need it to do -- protect the screen and give me the ability to prop it up.
It is similar to one of the GTAB sleeves, in that the device slips in and there's a fold that you slip between the device and the sleeve to hold it in place. Tiny velcro holds the cover in place, when it's closed (no magnets).
Caveats: No velcro on the back, if you want to hold the item open (easily fixable) and the camera in the back doesn't always fit exactly to the hole - they might have been better off making that hole a little bigger.
I got this at B&H when it was available for about 30 minutes, yesterday.
Android devices: ASUS Transformer, Notion Ink Adam, Cowon D3