It is not yet available worldwide as of this moment, but I got a unit at hand straight from Japan and here it is, the Nexus 7 Dock. The dock costs 3480 Japanese Yen from the Japanese Asus online store and you have a sturdy, well-built casing, a micro-USB port to feed power to the dock and a 3.5 mm jack for audio.
The packaging is also well made and simple. Well, when I say simple, you only get the dock and a folded manual. The manual also have different languages which suggests worldwide release.
The dock, however, have some requirements. First, your Nexus 7 should be running the latest iteration of the Jelly Bean, which is 4.2. I have not yet tried Nexus 7 with older OS and I will not be able to because all of my colleagues that have a Nexus 7 already have 4.2 on their tabs.
Manual
Ports
The Micro-USB port and the 3.5 mm audio jack can be found at the back of the dock. As I said earlier, the purpose of the Micro-USB port at the back is just to feed in power to the dock. The dock will not work and will not be recognized by your Nexus 7 without it having plugged in with power.
Nexus Logo at front
Asus logo at the rear
You need this to make your dock work.
The good news with this setup is that the power will now be fed through the pogo pins in the dock. This leaves the micro-USB port on your tab to be used for other purposes. Right now I am using it with a USB OTG cable and plugged in some peripherals like game controller and keyboard.
Nexus Pogo Pins
Respective connecting port on the dock.
Attach good quality speakers and plug in HD movies and you have a mini theater system. đŸ™‚
I admit, there should have been more to this dock like what most people expected, a HDMI port but the dock itself is fine. For instance, when docked, you can attach good speakers and you have a mini theater system, given the HD screen. Or, like what I am doing, I attach the speakers, use the micro-USB port of the tab to attach peripherals such as keyboard and mouse and I have a mini android desktop. đŸ™‚ You can also configure how the tab will react when docked:
Daydream options
Audio options
Overall, the dock is nice. It is perfect for your desk at the office or at home, whether you are checking some stuff over the internet or using it to search, say, some recipes for cooking. It is a great companion when you want to set your Nexus 7 up in a landscape, tilted position good for viewing what is on the screen. Oh yeah, you can use it as your table top clock, just make sure you do not push it off the surface when snoozing its alarm. :))
LifeDrive 
Does this also charge the Nexus 7?
Yup, rather than plugging your charger to the tablet port, you plug it to the dock then the dock has the pogo pins to charge your nexus 7