I saw it last time it aired, NHLFAN. Great show, and I believe that several minutes of content were added over the version that aired on the Travel Channel. You'll notice that DiscoverHD doesn't really have commercials, but this particular program still ran until just before the top of the hour. Unless my memory is poor, the entire segment on the monorail switching and repair station was not in the TC version.
Anyway, keep your eyes on the schedule as they have several other Disney related programs in HD. The recent
Disneyland program was running on the HD network, along with something from Discovery Channel that followed a group of people on many of the WDW thrill rides. I think this last one was called "Thrillmakers" or something similar.
When I originally got my HD service from my local cable provider, I didn't even bother to order the pay channels ($10 per month for the standard 4 networks). But I'm almost embarrassed to say that it was a Disney program that convinced me to get DiscoveryHD, and now I'm practically addicted to it. The programming is absolutely georgous.