Sorry, have to disagree there. I have no issues seeing my devices across the "g" and "n" networks with my previous gen TC (hosting "n" network) plugged into the netgear router (hosting "g") network.
Yeah, I have the opposite setup. I plugged my Netgear router into my TC and managed to get the Netgear into bridge mode. The TC does all the DHCP including my -g devices connected via the Netgear. I have 2 -n Airport Express's and 1 -g Airport Express all controlled using "Remote" via my -g iPhone. Printing from my -g PowerBook is equally seamless.
The Dual-band/Dual-network setup Does sound desirable for new adopters, but I don't think it's a reason for me to switch since I have successful separate g and n networks - and I'll be getting the new firmware (minus the separate network options)