Not true. The studios are split almost 50/50; well, 60/40 between HD-DVD and Blu-ray.
(and BTW, it's Blu-ray, not Blu-Ray--sorry, that was bothering me.)
And I agree wtih Deweyrules! that the change is too sudden. DVDs are certainly not the final frontier, but consumers may not be ready for the latest greatest thing, so let them release it, and if it doesn't work out, well, then we'll move on to even greater things.
Just one other note: Blu-ray has been out in Asia, albeit in a slightly different form that it will make when it premieres in America later this year, and it hasn't caught on much over there. And they're early adopters.