If you want to start talking of 45GB HD-DVD disk then you have to talk about the 200GB disk as they have been in development for a fair amount of time now. So going of that the gap goes from 15GBs to 155GBs. 1http://www.pcworld.com/article/id,117867-page,1/article.html
Anyway I think most people are missing the point of this ad. It's not to see if the PS3 is smarter then you, it's to show off it's power. Or it's power according to Sony anyway.
Offtopic: If you are going into price of the PS3 don't forget it comes with both a Blu-Ray player and Wireless card. Try getting those for the 360 and thats what another 300$ right there? Then you start talking about the price on online play since Sonys' is free and you'll start to see it's really not a bad deal.