Time Capsule is no doubt a great addition for the ease-of-use brigade but there are two small philosophical difficulties for the home network:
1. If the internal drive (up to 1TB) is used solely for Time Machine backups then it is not a NAS. From the forum responses on Time Capsule it seems many people are interested in using this as a NAS device. Can it be partitioned to allow for a NAS volume and still maintaining room for the Time Machine backups?
2. If it is used as a NAS (either in its entirety or a partition of it) then isn't it a little bit of a concern that in effect Apple are encouraging people to store vital household files centrally on a single disk with no RAID protection? It will be a significant single point of failure which could potentially wipe out a household's crucial files.
I am not suggesting that Apple should have offered RAID in the device as that would have increased cost and caused design issues but maybe they could solve these problems by allowing the external USB slot to be used for adding a second USB HD in the same manner as the original AirDisk was planned and have this as a RAID drive to protect the internal HD or, if people aren't fussed about RAID, optionally turning it into more storage in JBOD fashion.