This is one of those "sales pitch spins" from back in the LightPeak era. Now that TB is out, there little solid evidence to back that up.
" ... The spec for max trace length between the Thunderbolt controller and port is two inches, compared to up to 10 inches for Intel's USB 3.0 controller. ... "
http://www.anandtech.com/show/5884/...s-part-2-intels-dz77rek75-asus-p8z77v-premium
PCI-e and others have longer trace length restrictions than "raw" TB signals do. Sure, once you get to an amplifying transceiver the distances get bigger, but costs and internal space usage have jumped.
Back when Lightpeak had the possibility of building the transceiver amps into the controller that sales pitch made more sense. With the current design mandates of having active amp/transceivers in both side of the cable, it really doesn't make much sense in the PC space for internal deployment.
That kind of set-up requirements may make sense in a "large as a rack" computer, but not in the PC space. There are no 1-3 m distances to cover inside PCs in general. In fact, the general trend for PCs is to get smaller; not larger. So Thunderbolt doesn't really bring anything significant to the party distance wise. Fiber TB might cut down on internal RF problems. However, the fiber solutions for TB aren't all that much cheaper (relative to PC pricing norms) than other solutions already leveraged in larger computers already (bigger IBM boxes). [ Fiber being another one of these "Lightpeak" spins that hasn't show up in the marketplace. ]