Apple Thunderbolt Displays?
Tail wagging the dog.
There is a pressing need for a docking station functionality for a Mac Pro? The thunderbolt display is a docking station that happens to have an LCD embedded. It has a fixed, relatively short, length cable attached to it. The Mac Pro doesn't need power supplied to it from a docking station. There are far better displays can get for the money for a Mac Pro.
The TB display doesn't connect at all to standard PCI-e GPU cards. The GPU attached to the TB ports on a Mac Pro is likely embedded.
Unless the Mac Pro is stripped of the vast majority of its PCI-e slots, Thunderbolt doesn't solve any problem the Mac Pro has.
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I'm with you to a degree here.
The way I see it, it's useful if one has spent money on TB devices
In the context of current Mac Pro user base which has had more money spent on it:
1. TB devices
2. Expensive PCI-e cards and/or external SAS/eSATA storage units.
I can see the "future money will buy TB" trend. However, already capital costs spent aren't not going to be driven by Thunderbolt on an overall market scope.