Time Machine backups from Leopard can now fly through the air with the greatest of ease, not just over a Wi-Fi network to another Mac running Leopard, but to a new "backup appliance" called Time Capsule. According to Steve Jobs, the Time Capsule is a "full 802.11n AirPort Extreme Base Station with all the ports in the back." Showing a slide with a laptop connected to an external drive, Jobs bemoaned the annoyance of connecting and disconnecting the cable.
Time Capsule, which looks like a larger version of the square AirPort Extreme Base Station shipped in 2007 (7.7 inches or 197mm versus 6.5 inches or 165mm), is intended to back up multiple Macs - for instance, all Macs in a household or small office workgroup - and it includes either 500 GB or 1 TB of storage. The new device costs $299 or $499, depending on drive capacity, which puts the 1 TB model at a bit of a premium in comparison to the average prices of raw drives.
Time Machine currently cannot back up to a NAS (network-attached storage) drive, such as one that you might attach via USB to an AirPort Extreme Base Station. Apple originally promised Leopard would include AirPort Disk backups to AirPort Extreme-connected drives, but that feature was dropped prior to Leopard's release.
While 802.11n can offer speeds as fast as 90 Mbps when using the less widely used 5 GHz band, it also supports the slower 802.11g (roughly 20 Mbps at best) and 802.11b (5 Mbps) standards - supported by the original AirPort Extreme and the original AirPort. Backing up over 802.11g or 802.11b could be painfully slow and clog the rest of the network.
Given that Jobs announced software updates to other hardware devices, such as Apple TV and the iPod touch, at the keynote, the lack of an announcement about the existing 802.11n AirPort Extreme Base Stations would seem to indicate that Apple does not have an update for them that will enable Time Machine support for NAS drives. That's strange, since it would seem that the technical problems that reportedly caused AirPort Disk support to be dropped from Time Machine would also afflict the Time Capsule, so perhaps a future update will offer that promised functionality. Apple also gave no indication when Time Machine will fully support FileVault encrypted user accounts, another important feature for security-conscious mobile users.
Time Capsule also works as a NAS volume, along with any additional drives you attach via USB to Time Capsule.
In the years we've written about backups at TidBITS - starting with floppies; moving through early, middle, and late tape systems; and continuing now with hard drives - we've consistently complained about the lack of a simple, configuration-free software and hardware offering that would pair with a Mac. Now we have it.
For those who haven't already settled on a serious backup strategy or invested in backup drives, the Time Capsule may prove to be a popular device, especially for backing up multiple 802.11n-enabled Macs on the same network. For a single Mac, if you can cope with the horror of a cable, a regular external drive is a significantly cheaper option. Further, Time Capsule seems best for those who don't already have older gear or an established backup strategy: those who already have NAS drives and AirPort Extreme base stations may be frustrated at the apparent lack of an upgrade path, and those backing up Macs with slower 802.11 standards will likely find that Time Machine backs up too slowly to be usable. However, in shipping Time Capsule, Apple has further emphasized how serious they are about Time Machine as a core feature in Leopard.