So to sum it up HD-DVD is better for the industry in the short term (costs them less money, although that is arguable). Blue-ray is the better technology and better for the consumers now and in the long run (capacities up to 200GB).
The only reason I see not to choose Blue-ray over HD-DVD is if Sony charged a licensing fee for the technology. Of course, I don't see any news that HD-DVD is going to be open licensed either...
So my vote is for blue-ray. 50GB versus 30GB is a no brainer.