Re: How many people ACTUALLY upgrade ram???
Probably close to zero. None of the current 21.5" models can be user upgraded because there's no access door.
I used to repair these things, to change/upgrade the RAM, you have to remove the screen/glass, and main logic board etc. to get at the DIMMS. No especially difficult, but it is more of a challenge to stick the screen back on afterwards. The process requires special tools and a lot of swearing,
I'm sure iFixit.com have a how-to guide. you will invalidate your warranty if you try,
The 27" iMac, Mac mini. Mac Pro and 13' Macbook Pro without Retina Display can all have their RAM upgraded by the end user.
This base model will probably be aimed at education and those users that just want to do Internet shopping, email and Skype/FaceTime their grandchildren but don't want to get an iPad.