The Henge docks were pretty good for previous models, but I don't think they'll work for the new ones, because the new ones have ports on both sides -- so there's no way for a dock to just connect to one side.
I assume Apple is trying to kill the docking notion. Closest they have is the Thunderbolt display, which gives you firewire, ethernet, USB, power -- the monitor supplies a magsafe connector -- all in one. Down side, it also gives you splitting headaches unless you're using it in a completely dark environment. 😛