Thunderbolt was pretty clearly envisioned as a way to move real-time video data. As others have pointed out, there is little benefit to audio data over cheaper and more widely supported protocols, and for the average computer user no benefit at all. The other possible utility would be in linking multiple computers for parallel processing, but users who need that kind of power are more likely to go for the cheaper and certainly easier alternative of buying an equivalent parallel processing computer, rather than trying to get all the desktops in the building working together.
Still given the history of computer technology being marketed the way muscle cars used to be promoted, I would have expected the manufacturer's to have jumped on the bandwagon just so they could sell to the power mad. Unfortunately, thunderbolt has come along at a time when most users are realizing they do not need a real computer at all to decorate their FaceBook wall or follow the tweets of their favorite celebrity. When the most popular computer does not even have a USB port, there is little reason to hope to sell an expensive and useless idea to the masses. And given the troubled history, and doubtful future, of Firewire I think it is not too likely that Thunderbolt will ever appear in most general purpose Windows machines.
Although motherboard manufacturer's might be tempted to market a few products to the crazy gamer community, the future of purpose built computers based on a small market for specialized motherboards is itself in doubt. Many off-the-shelf gamer machines will now satisfy the needs of that community. The serious video editing community is a still smaller market. The occasional very high priced specialty workstation may be available with thunderbolt, but the general market will probably not support its adoption as any kind of standard component. And without a general implementation of Thunderbolt, the return on investment in peripherals to connect to the few machines using it will create a death spiral.