There's no doubt that if too many developers impose obligatory installations, the PS3 experience will start being closer to the ZX Spectrum experience in which you had to wait 3-6 minutes before playing a game...
Well, at least you have the option of getting a bigger hard drive, but I'd be pissed off if I was forced to do so.
My Mario Kart Wii friend code: 2707-1866-0957