You will care alot when IOS 6 doesn't run (or runs in hobbled mode) on your iPhone 4 because it doesn't have enough RAM.
Agreed. So tell me why, if I'm upgrade-eligible right now, why I wouldn't just wait until I need the A5 processor to upgrade?
No sense ruining an upgrade credit when you can wait for a phone with better specs (LTE, NFC, better screen, better build materials) later, in time for iOS features that require it.