The later iterations have added the ability to upload both gcode files for printing and the config.g file to setup your printer. Its well worth checking out if you have not done so already.
I had always planned on getting a Mendel90 with the Duet up and running on my wireless network. Originally my intention was to use an old Wireless LAN router I had spare but in the end I have gone for an wireless "nano" router:
|(image from TP-Link website)|
Setting up consisted of connecting via ethernet to the router, setting the IP range to match my wireless network and connecting it to my WLAN in client mode. Turns outs its really quick and easy to add wireless capability to the Duet.