Ha, good question. I think Apple's on the Blu-ray bandwagon if I remember right.
I think there's a better chance of seeing Blu-ray in desktops like the Mac Pro before the laptop. Even if it hits the Mac Book Pro, I guessing it's going to be the most expensive build to order option, just like the Dell.
If you really need a laptop now, I would just suggest not waiting and buy something. Technology will always out date itself six months later, no matter what you buy. You could always add an external Blu-ray/HD DVD drive later if need be... anyways, just my 2 cents.