The latency involved with anything but a LAN would seem to be too much for true real-time collaborative tracking, as opposed to tracking remotely to a locally sourced playback.
Where I see this REALLY being a deal-changer is for hobby/small studios (or where the bedroom has overflowed into the loungeroom!), where the mixing/control room is separate from the studio(s), because ALL communications, including HD audio and video, can use a SINGLE Gigabit Ethernet (GbE) cable.
Drums and amps in separate, dedicated rooms, but all part of the same session, enabling visual synergy with audio isolation.
Of course, the studio computers have to be silent (home theatre PC?) and have their own audio hardware, but simple two in/two out devices may suffice for solo vocalist/instrumentalists. The Dante audio system has shown that large numbers of HD audio channels can be handled over Ethernet with around 1ms latency.
No more multi-core runs between rooms! And cheap GbE LAN hardware (switches) can be used.
The studio PCs could also be used for show a window for cue sheets or lyrics.