I am hesitant to speculate on whether Thunderbolt will be a success. The 10Gb transfer speeds (copper today, fiber and 100Gbs tomorrow) are attractive and the ability to boot from it makes for a compelling case. But the fact that only Apple has built cables that work for it (they are active cables, require chips and processing at both ends) will certainly hinder adoption, just like firewire.
But unlike Firewire, these things can be used for some really cool stuff. Here's Sony showing off what I think is novel and cool: the notebook has one type of graphics card, the dock has a kickass graphic card. IMO this would kill a lot of the complaint about notebooks - they're great for the road, but I need more oomph at my desk. This would allow for a single box to power two different modes of processing - mobile and desk. I like it.
Check it here:
http://www.macrumors.com/2011/06/27/example-of-an-external-dock-and-gpu-over-thunderbolt-technology/
