The barn:
The majority (51%) are not bothered whether it does or doesn't return. Only 12% don't want it to return at all. 38% want it to return (19% as is/8% minor improvements/10% major improvements)

Re-entry heating:
Only 8% do not want it in any form. Admittedly I forgot a 'n preference' option but 23% want it added 100%, 69% want it to be a difficulty option but not mandatory.

Planets:
48% want more, 11% don't and 41% do not mind.

Landforms:
Very popular, only 1% do not want it at all. 13% have no preference but 86% do want it.
32% want them to be purely aesthetic, the other 68% want them to be active.
Side note: Obviously this would in reality be a bit heavy so not possible but if it can be done, it is certainly wanted. Personally I would happy if there was just some inactive landforms, just to give more purpose to exploring.

Weather:
84% of people want weather. Out of these people, 70% want it as a toggle-able option. 5% don't want it and 12% have no preference.
69% of people said they want the weather to be both 'Just for show' and active so that it affects you're flight but with the option to change between. Individually 17% said 'just for show' compared to 14% voting for active weather.

Other visual improvements:
6% are happy with the way it is and don't want any improvements here. 50% would like model/texture improvements. The largest portion, 74% would like clouds, 52% for city lights, 56% for collision effects and 36% for mist.

Release cycle:*
The lowest portion, 10%, want updates to be released more often with fewer features. 41% want long gaps between updates but updates contain a lot more features. The final 49% want something in between.

So what does all this mean? Obviously with only ~9400 responses, this survey can't represent the entire KSP community, however it is a good indicator. With only 12% people not wanting the barn at all, and Squad have said they're improving it - it should return.
Re-entry should be added as a difficulty option - Implementing deadly re-entry should require little effort I would imagine.
A few more planets would be appreciated but landforms on existing planets had an even better reception - even if they were just for show!
Weather is another largely requested feature. Personally I think it should just be aesthetic so it doesn't add to much stress, and obviously should be a toggle-able option. Simply adding some clouds and having some rain/snow shouldn't be too stressful.
Other visual improvements didn't get much more than a 50% vote so could be considered but most people wouldn't be too bothered if they weren't added - there are always the updates after 1.0.
And finally the release cycle should be somewhere in between long wait, more features and short wait, less features - which is where I feel it is now so no changes needed there.