I think the PS3 would not have been possible in it's current form without blu-ray and cell for gaming purposes. In terms of the design ideas of the PS3, they have been beneficial.
However, not having them would have caused another 5 - 10 million to be sold up until this point in my opinion as the price would have been much more in line with consumer expectations.
I'm loving mine right now, it's really come into it's own since the launch of the slimmer version. I'm glad Sony went for the Cell and included a blu-ray player!