I just want items that wow me and change the way you can play the game. Right now all you have is "more dps" or "better defense", like 8 or so stats that only work for one of these 2 concepts. At best you can consider it game-changing when you gear to a threshold that allows you to perma-run one of the skills that are meant to be oh shit buttons like archon. Removing the rune concept from itemization and just putting it on the level curve was probably what flattened their itemization plans, but that choice was made pretty shortly before release so the repercussions only showed after the game was out.
They need to streamline current item mods somehow and then throw a ton of mods in that enhance/change specific skills so people can actually make a variety of builds for different skills.
Their first pass over for legendaries was changing them from crap to BIS stats with a funny proc. An improvement for sure but they could do better.The big selling point of legendaries right now: "dps stats you otherwise dont get in that slot" ... while nice to a degree thats still mostly boring and also often removes any equipment choice from that slot. Instead legendaries could maybe grant special skills (similar to the way D2 runewords did, but new skills instead of those of other classes), focus on making them unique and interesting and not just being the top dps choice.
I also think they should take the cap off from paragon levels. Make them take more even xp beyond 100 and let people that want to grind it out. The effects at that point are negligible enough anyway, and at least you feel some progress after a weekend of playing without any noteworthy drops. Friend of mine that still plays already maxed out all classes he enjoys. In D2 you'd roll a different build at that point, but theres no reason to in D3.
Re: PvP: In D1 and D2 you just didnt have a ton of extra rules, special zones etc for PvP. You switch it on and that's it. I wouldnt mind if they found a way to put that back in. But isnt the brawling stuff ok for low-level dueling? I was so glad they canned the idea of copying WoW arenas because that would lead to balancing (lol) around it, even if they initially say they wont. I hope the whole notion died with the change to brawling.