Oh, and the 360 version maxes out at 720p as well.

Incorrect. 1080p on the 360.

http://www.ripten.com/200...ipte-blogs-press-release/ 
And a question for you Tondog. Do you find this to be the possible start of a trend of large download requirements to the PS3? I mean, with GTA4 coming up, is it possible that it would require the same thing in order for the game to run smoothly?
And while I agree that small (under 1G for example) downloads are no big deal, if a consumer is purchasing a 40G PS3, 5GB seems to take up a pretty large percentage of the HD space imo.
Well, here's my take on the whole installation thing...
Large (say, greater than 1GB, going by what you suggest would be large) installs are nothing new for PS3 owners. What's nice is that you can actually find out how much hard drive space is required by simply looking at the back of the game in the area where it lists all the features it supports (kind of like what you see on the back of PS2/Xbox/360 games). Most of the times what's listed there is accurate, sometimes it's even more than what is required. For example, Skate says that it requires at least 3GB of hard drive space when in actuality, my PS3 says that the game data on my hard drive for Skate is just 2.5GB. However, sometimes what's listed isn't even close to being right (I'm looking at you Ratchet and Clank! 420MB is not the same as 510KB).
Most of the time, the large installs are found in third party games. As I said, Skate requires 2.5GB, Assassin's Creed needs 2GB, Heavenly Sword requires 2GB as well, and there's countless others. Just go into GameStop or something and you'll see what I mean.
I wish these humongous installs were optional like in Unreal Tournament 3 (2.5GB) or Ridge Racer 7 (5GB, same as DMC4), but if they need that space, then I'm fine with it. At least you can delete the installation data whenever you feel like doing so in the PS3's menu. The thing that I wonder is why certain developers need all this space when Call of Duty 4 only needs 12MB or Uncharted: Drake's Fortune, a game with
ZERO LOADING TIME has no installation. One of life's great mysteries I assume.