I borrowed an Airport Express a while ago and was pretty happy with it. My parents' wireless router broke down a couple of weeks ago, so I gave them mine and I got a shiny new Airport Express for Christmas. Turns out there is a way to get Windows to use an unrecognized printer attached to the AE after all. In a nutshell, you connect the printer to the computer's USB port and install the software normally, connect the printer to the AE and follow's Apple's installation instructions with a dummy driver selection, then change the driver in the printer preferences.

The port forwarding options remain a bit of a nuissance. It only allows one port per entry, so I had to add a lot of entries for things that use port ranges.