Nexus devices might be a great deal compared to other devices in the market, but you pay the price when it comes to accessories. They're either horrendously expensive or take so long to go on sale it's almost time for a new version of the device. We might be lining up for the second one here, as Asus has just now posted English listings for the wired and wireless charging docks for the 2013 Nexus 7.
Asus started selling the wireless PW100 dock in parts of Asia and Europe in recent weeks, but we're still without an official announcement stateside. However, Asus' full product pages hit most of the relevant points for both versions. The wireless dock is basically a triangular stand with Qi charging built-in. It looks like the tablet is supposed to be placed on in landscape orientation – some (poorly translated) Japanese reviews seem to indicate it won't work in portrait.
The wired dock has the same kind of shape, but this one is an angled slab with the triangular bit at one end. That's where the tablet plugs in for both power and HDMI out. the dock can also be stood on its end and used as a keyboard stand.
There is no US pricing listed anywhere on the Asus site, but the wireless dock has been selling for the equivalent of roughly $50 overseas (through Amazon) and a bit more from Asus. Hopefully the appearance of these listings means a US release is coming soon.