BDROM won't be with us until early next year if you believe Sony. Its an expensive media and they, Sony, are still working on manufacturing process, etc, etc. I actually doubt BD will be seen in other consumer electronics other than the PS3, and like I said, it will be expensive. So for now, the dev companies have to use regular DVDROM drives.
it will be seen in other consumer electronics, but what you said is the reason why HDDVD will win, like VHS won over BETA. The production cost will be higher for the next gen, but if the media cost is higher too, Then games will be expensive as hell.
Honestly I don't think we'll see either take off in the USA, being the backwards cave dwellers we are. It took us forever to adopt disk based media after all.