They are very missleading in their advertising. These companies DON'T hire from these schools. They hire the guys that do this stuff on there own just like you and me. In fact, I talked to my buddy at EA and he said most of the game designers come from the testing department. This is an entry level position!
I've lost count of the number of times I've tried to tell people that. I know any number of people enrolling for these courses, and I'm sure most of them are wasting their money.
If you're interested in this and you can do it, then it sounds like a good idea. How much time and expense do you plan to put into marketing it though? Without good marketing, it probably won't go anywhere for you, which would be a shame. If I were you, I'd talk to some of the sites that specialize in these kind of training DVD's and see if they'd be interested in a range of game dev themed ones.
Kurv Studios is one that springs to mind. Gnomon is another. In fact, I think Gnomon may already have one or two on game dev themed modelling or animation, so they would be good people to ask.