Over at Macworld, Glenn Fleishman has an initial hands-on report about Apple's new Time Capsule combination Airport Base Station and NAS, and he's confirmed something folks were wondering about: "you can also perform Time Machine backups to drives attached to the Time Capsule via USB." This is interesting, because Apple originally said that Time Machine backups would be possible to an AirDisk (that is, an USB external drive on the regular AirPort Extreme Base Station).
Just before Leopard shipped, that feature quietly disappeared, leaving some early-adopters who had counted on that capability in the lurch. The obvious questions now are whether there's any technical reason why Time Machine to AirDisk wouldn't work on the AEBS, and whether Apple is holding the feature back just to promote the Time Capsule. In any case, it's good to know that if you get a Time Capsule you're not limited to the internal storage, perhaps making the smaller 500GB model that much more attractive.