Just browsing Apple's site - prior to today, if you wanted to upgrade RAM in the 21.5" iMac, you were SOL. Now, it says Apple or an authorized Apple repair shop can upgrade the RAM after purchase.
This is good news since I'm fine with 8GB now but what if I get into audio/video editing in a year or so? Now, I can upgrade my iMac's RAM.

This is good news since I'm fine with 8GB now but what if I get into audio/video editing in a year or so? Now, I can upgrade my iMac's RAM.