Usually, when a new technology comes out from Apple like Thunderbolt, (mini display port in look a like), I usually think "Why would other "non" Apple manufactures like WD, Promise etc... adopt Thunderbolt? as USB 3.0 or eSATA is their bracket... where as Apple likes to keep to themselves only tailoring to their own devices (eg. using WDS (or extenting wireless via Airport Express), for example. is not possible unless you have Time Capsule (Apple) )
I guess I was wrong when I saw this one on MacRumors.
The major difference between TB and FW adoption is that FW was 100% Apple whereas TB was envisioned by Apple and then handed off to Intel for development and implementation.
Since Intel is a major supplier of MBs to PC box manufacturers it can more easily push TB than Apple could FW. Moreover USB 3 is an Intel creation too so it has even greater power to play puppet master.