I don't know which format is truly better.
Bluray has more space but is more expensive. It also has a data transfer that is superior.
But if all people care about most is the place, what do you think would happen if the cheaper HD-DVD would suddenly get their 150 Gb (ten layer) models out, ready to be read?
Sure, they'd cost more, but Bluray would probably see this as a challenge, and up the storage capacity a few steps more, to show that it has the advantage in ROM department... however... who's going, in the movie or game industry, need even 100 Gb anytime soon? What sort of padding they're going to use to legitimate such storage spaces?
Heaviest games which eat a few Gb of space once installed still hold on DVDs for the moment, and for PC, I'd rather pay two DVDs (not even HD DVDs) and wait a little longer, but pay less, than grab the "next gen" storage discs.
I don't think the change is going to be that radical, and we might get an amusing switch in the balance in the near future.