If even after watching the Nexus 7 drop test, you’d still prefer a little extra protection for your tablet then the official Nexus 7 case might interest you. They where initially available for pre-order bundled with your Nexus 7, but quickly went out of stock. Recently people have even been selling them on eBay for as much as $100. However they are now back in stock in the US play store for $20 (still no sign in the UK).
From the pictures it looks like you need to remove the tablet from the cover to access the power and volume buttons (correct me if I’m wrong), so I’m not that impressed with the design. I went with a really nice £8 ($12) Terrapin Folio PU Leather Case which allows full access to all the ports, automatically turns the screen on/off on open/close and has a build in stand.
So unless you’re the type of person that must have the official version, I’d recommend shopping around. There are already some very good alternatives available.