We've confirmed the security flaw with our own Smart Covers and iPad 2s running iOS 5 and it's just like the video above—the bug easily exposes your iPad 2 to unwanted eyes. And though you have to jump through a few hoops to get there, it works like this:
• Lock a passcode enabled iPad 2
• Hold down power button until it reaches the shutoff slider screen
• Close Smart Cover
• Open Smart Cover
• Click cancel
I don't know how anyone would've figured that out but it definitely works. Going through those steps exposes an iPad 2's entire home screen and apps (you can delete them but can't open any apps) and even Spotlight previews. Perhaps more damning is that if you have an app open before you lock it (like Mail or Messages), the user who broke into your iPad 2 will have full access to that app (and can see and send messages, etc.). The smart cover break in is limited, yes, but could be used maliciously to peep e-mails that weren't supposed to be peeped.
The only way to fix this bug is to disable Smart Cover unlocking in the General settings menu. Annoying for Smart Cover owners but a workable stopgap solution until Apple fixes the bug. [9to5Mac]
You can keep up with Casey Chan, the author of this post, on Twitter or Facebook.