There is a way to print from a windows computer over wireless, though I've never taken the time to set it up. MY AP extreme can be used to print wirelessly, as I think the AP express doe, but I have an AIO printer, and to use full funtionality it's best to hook the printer into another computer rather than a router, so that's what I do to print wirelessly.
AP express has been out for a couple years, I don't think they'll replace it until the next generation of WiFi comes out. Something to be said for a wireless router that fits in the palm of your hand though.