I read somewhere that the only place they expect the trains will go that super fast bullet-train-esque speed will be in California so I wouldn't expect the train going from Orlando Airport to Disney going 100+ mph. I don't think even the Euro-Star goes that fast in urban areas. I know when I went from London to Paris by train I remember them telling us that we didn't really get to the high speed part of the ride until we hit the Chunnel.
I'm actually really excited about this development. I'm a big fan of areas that have good public transit systems, especially when I travel as I usually don't rent a car unless I can't avoid it as I get lost easily in unfamiliar areas. I love Europe's rail system, as well as what's available through Amtrak in the Northeastern US and MetroLink in Southern California, and am always excited to see steps taken toward getting a light rail systems set up here no matter how small. It'll take eons before we have anything to match what other industrialized nations have (if we ever even get there. I'm not holding my breath!), but every step helps. I think it'd be really nice if I were not only able to get from the airport to WDW by train, but take a trip into Celebration from Disney property without having to call a cab or have a car. If the Sunrail prices are anything like the Metrolink prices in California, taking the train could be much cheaper than a cab or towncar. On Metrolink, you can take the train from LA to Anaheim for about $6-8 per person one way, depending on the day of the week and assuming you buy tickets a la carte and don't get a pass or roundtrip ticket (which should be less). I assume the prices would be similar.
I don't blame Kevin for not being too excited about this as I'm sure that it probably won't change the way too many locals move about town. But I think this could be wonderful for tourists and business travelers in the area, especially if they ever end up expanding the line out to places like Port Canaveral, St. Augustine, Daytona or even down to the Keys after they build the leg from Orlando to Miami.