The main thing that strikes me about this thread is what a difficult job WotC has ahead of them. I love the ideas and generalities I've heard in regards to 5e so far, but man, when the rubber starts hitting the road, some folks will be happy, and some won't. And I'm the same as everyone else--just hoping my preferences make it in:
An easy +2 for Combat Advantage? Sure.
Yes to rolling to confirm crits, but only if crits actually mean something as in 3.x. If they stay as max damage, then critting on a single 20 is fine.
Standard/Move/Minor or Full/Minor actions.
Iterative attacks, but with a limit.
AC that doesn't scale with level.
I will roll for stats whether its included in the rules or not.
At will (low level) spells and cantrips.
Implements that enhance spell casting (and have proficiency bonuses).
Sustainable spells.
Alignment, 3.x style, that has strong mechanical effects.
Simple, easy to read, but robust and comprehensive stat blocks.
Yes! to frightening and significant effects--if not level drain, then something as evocative and powerful.
Paladins using Detect Evil to spoil plotlines is also an annoying aspect. If I want some demon possessing a local lord as part of my plot, I don't want that ruined by the application of a readily available class feature. Lame.
And sorry, but I have to address this, because as a proponent of strong mechanical effects of alignment, it just strikes me as plain wrong. Simply knowing that the local lord is possessed shouldn't end the adventure, it should start it! You know the truth, but no one else does, so how do you get past the lord's guards and defenses? How do you convince the rest of the town of the truth? What if the demon, knowing you have the drop on him, turns the tables on the party?
A good DM isn't just a good adjudicator of rules, but also a good storyteller, who can adapt to what the party does and keep the adventure rolling. Villains played at the top of their intelligence will not so easily be vanquished.