Third-party vendors will sell adapters, available sometime this spring, that let you connect USB, FireWire 400, and FireWire 800 devices to Thunderbolt ports. Thunderbolt won't make these legacy devices any faster, however--they'll still be limited to the performance of their built-in components. For example, a FireWire 800 device still won't be able to transfer data faster than 800 Mbps.

As noted above, Thunderport can carry data, video, audio, network data, and power, so we also expect to see adapters providing audio and Ethernet connections. Perhaps we'll even see cables that grab power from the Thunderbolt port--this could be useful, for example, for getting some extra juice for an external USB or FireWire peripheral.

You can connect up to six devices to each Thunderbolt port by daisy-chaining them--connecting the first to the Thunderbolt port, connecting the second to the first, and so on. Of course, this requires that each device in the chain have Thunderbolt ports (or two other types of data ports along with Thunderbolt adapters)--one to connect to the device in front of it and one to provide a connection for the device after it.