Thunderbolt having direct memory access makes me slightly uneasy. I'm more inclined to fill the ports with superglue than actually find a use for them (I won't mind you). If the price of the accessories comes down, then it'll certainly be an incredible boost for some applications.
If anybody is interested in learning about them, there's direct key stealing attacks for both TB and FireWire if you look around.
Thunderbolt devices are currently a joke. The use case would be being able to push a laptop's GPU out to an external display card, so when you're docked you can run whatever desktop GPU you want.
But the cheapest connectors for that sort of thing can't to x16, and cost $800. Which, for the price, would let you buy an entire desktop.
The use case would be to connect to the dock with 1 cable rather than a huge port on the bottom. Or connect to an external drive bay for fast and low overhead access.
The external GPU thing has always been the most fanciful use case.
If anybody is interested in learning about them, there's direct key stealing attacks for both TB and FireWire if you look around.