After the installation was complete on Sunday, I connected to the administrative web page of the Actiontec router that Verizon had provided (and which is required with the Verizon TV package). I reconfigured the router to take over the network name (SSID) that I had been using on my AirPort Extreme, changed the security to WPA2, and set the passphrase to the one I had been using previously. Our laptops and my iPhone picked up the change, but my AirPort Express units (which provide wireless printer support and AirTunes) didn’t. They’re first generation AirPort Express, and do 802.11G and 802.11b only.
After some pulling my hair out this morning, I found a thread on the Apple support message boards that suggested that the original AirPort Express was incompatible with the Actiontec version of WPA2. I changed the Verizon router to use regular WPA and told the AirPort Express to use WPA/WPA2 for authentication. After rebooting, I finally got a good connection (green light) with the Express. My second Express didn’t need any reconfiguration–I simply unplugged it and plugged it back in, and it worked.
So there’s that. What’s left is getting my hard drive, with all my music, back on the network. I may have to run an Ethernet drop into the living room over Christmas. Or try one of the tricks for supplanting the Actiontec for wireless.