I am probably their biggest rMini user/fan. In addition to what you mentioned, I truly hope that they upgrade the speakers to where one can even hear them. I'll be upgrading my mini anyway but it would be nice to have those additional features.
I hear you. The retina mini was by far my most used Apple device last year. It was really tough to sell it....but, I got a good price and I'm ready to go when/if they release the new one this month. The 6+ has been doing a reasonably good job of filling it's shoes in the meantime.
In order of importance, here is my take on the improvements I would like to see in the next GEN mini:
1) Address the gamut issue. I may be in a minority on this but to me it's a real weakness in the current mini's.
2) More RAM: Current ram really limits multitasking. Constant Safari/ other refreshes are a big drag on productivity.
3) Other display improvements: Decrease in reflection & increased brightness.....to make using outdoors in bright conditions easier.
4) Thinner and lighter: I'd be happy if it returned to the size of the original Mini. Smaller bezels would be nice.
5) Better speakers: Front facing speakers top and bottom sure would be nice.
6) Touch ID & NFC: I travel with the Mini on business....would be a nice feature.....not critical though.
Not sure how many of the above we will see. I'm assuming the Mini will be faster, have a camera upgrade....so I'm almost taking these as a given.
Items 1 and 2 In the list is are deal killers for me if not addressed. It's going to be tough to plunk down several hundred dollars ($600 + for the cellular model I'd likely buy) and have to deal with these issues for at least another year.