Apple has released updates for Time Machine and Airport, giving us three update reboots in three days. The update improves Time Machine compatibility with Time Capsule
and offers some fixes for AirPort
drivers. I don't, at this point, see any indications of the rumored Airport-Extreme-as-Time-Capsule abilities, but I'm assuming that will require an Airport Extreme firmware update.
The update is available through Software Update.Thanks to everyone who sent this in!