I would also love to hear the answer to this question, as I'm in the same boat.
I actually uninstalled my trendnet wireless G router in Network Connections and then followed the Guide installation instructions after plugging my wireless laptop into the main internet box from rogers.
I am now connected via the new DIR-615, but not wirelessly! I have gone into the IP address listed for the DIR-615 router and configured it, and was able to connect wirelessly for a couple minutes, but have since been dropped and now absolutely cannot connect wirelessly again.
Are there any users out there who can offer advice? I have three computers that were previously connected wirelessly to a G router, and would love to not return this N and re-install the G.
Thanks!