http://www.businessinsider.com/bullet-train-from-las-vegas-to-nowhere-2012-3
Going to Victorville is dumb. If it's built, I hope that an extension from Victorville to Los Angeles is constructed soon after.
As someone who lives in Las Vegas and drives to Los Angeles relatively frequently, I can tell you that a high-speed line between Las Vegas and Los Angeles would be a good thing. For one thing, the traffic on I-15 is horrible, and the road itself devolves into a pitiful 2+2 lane road, with large 1+1 segments; for hundreds of miles the road surface and the surrounding infrastructure is in a state of disrepair, and the cost of repairing and improving I-15 would easily top $4,500,000,000. And even if I-15 were repaired and upgraded, a high-speed train, going 150mph all the way, would make the transportation of cargo much more efficient, which is a big concern since most of the traffic on I-15 is big-rigs.
It's conceivable that regular, fast and reliable passenger service would help improve the economies of Las Vegas and Los Angeles by making both more easily accessible to the residents of the other, but only if the prices were dramatically lower than airfares [or if the experience was more pleasurable, which isn't hard to ensure once the TSA personnel is out of the equation].
Hell, I would be a proponent of extending the line from Las Vegas to one of the Phoenix suburbs for the same reason: the roads from Las Vegas to Phoenix also stretch hundred of miles as old, poorly surfaced 1+1 highways with no divider, and high-speed cargo service could beat the caterpillar of big-rigs perpetually inching up and down the road at 45 mph.
But should the Federal Government be helping to finance this? Not really, no. At best, they should provide tax-breaks or expedited processing of necessary permits.