I definitely know what I want from EU3 expansion (maybe DW, maybe next one, hehe).
I wanna changes in diplomacy. I'm tired of unrealistic and "wanna-cheat?" diplomacy system. What's the point in "Unlikely-Likely" chances for agreements? Why should I ever try to arrange "Very Unlikely" alliance? I will get 20 rejections, lose 20 diplomats and spend all my good relations before arranging an alliance! Or should I cheat and save\load? Nah, It does not worth it! Also, If there are doubts for my neighbor to ally with me, why I can't propose better conditions?
In my opinion, Paradox already made much better system that can be used for agreements. It's not ideal, but more realistic and fun. Make them to work like missionaries! We choose agreement, we see our %/per month chance of accepting, we choose if this offer will be unlimited, or will be auto-cancelled after some time. And voila! Our offer is now in process of arranging (very realistic). All our "very likely" agreements will be made in a couple of days (also more realistic then current "right-after-clicking"), others will be made in months or years (of course if they are not "Impossible" or "0%/per m"). Such system will even make possible to send numerous diplomats, without current stupid "diplomat in route" limit.
What do you, guys, think?