Without further interruption, here's the 3/12/12 article, with my insightful and occasionally annoying comments. You can peek at the original article here.
What are your thoughts on critical failures and things like injury charts and tables? Is this something that you could see living in the core of D&D Next or a module?
Those are two great examples of things that probably wouldn't be core assumptions, but could live as modules, albeit in a core book (I thought the modules were going to be published separate from the core. and is it just me that has an issue with the term "modules" referring to optional rules after TSR and WotC have been using it to describe adventures for years?). Neither of those two have been consistent in their presence across the breadth of D&D (I'd argue they never really where there, except as optional and / or house rules), but while I wouldn't consider their presence to be core to the assumptions of the D&D game, they're prevalent enough in auxiliary materials throughout the years that they seem like good candidates for things that DMs should have available to add into their games (my lord, but this sentence is so full of fluff. "They were never core, but enough people house ruled it in we figured we'd give you the option to play with out house rules").
Off-turn actions of all kinds can be a double-edged sword. On the one hand, it can be exciting to be able to break the turn order and step in when you normally couldn't, giving the player a lot more control over the situation. On the other hand, off-turn actions are one of the primary sources of game play slowdown—not simply in their resolution, but in the player's need to keep them in his or her mind all the time (this would certainly effect their "60 Minute D&D Session"in a negative fashion). We've all seen the situations where the DM is well into resolving an attack when one player says, "Oh wait! I have a power that lets me stop that."(I've never seen that, but I don't play 4e and barely played 3e) That's not so bad when a single player has a single off-turn action, but when they proliferate across multiple characters (with some characters stocking up on off-turn actions), you can see how something that is good in moderation can bring the game grinding to a crawl. (is this why 4e combat takes so long?)
I think one of the good things that off-turn actions do is give a sense of that the PC has active defenses; I don't just sit and take the punishment that the DM dishes out, I have a chance to protect myself thanks to the character building choices I made. This is one of the methods by which saving throws as presented in editions prior to 4th Edition actually have a positive impact on the players' game play experience. (I don't see how a Saving Throw is part of a character's "building choices", as it was always built on a set table based on class)
Going forward, I think we'll want to address the challenges associated with off-turn actions in a couple of different ways. First, I think we'll want to be more cautious with how many we inject into the game. ("Because we see how slow encounters have played out in 4e, and we don't want a repeat in 5e") In order to retain the benefits of the "active defense" side of off-turn actions, we can look to saving throws as a method of providing that feeling, and then build mechanics that ride on top of the saving throw if the player chooses them (I'm interested in seeing how this actually develop, as it makes no sense to me as stated, but maybe it's because Rodney "knows" but can't explain it yet)
While I don't think level 0 play will be an assumed part of the core game (0 level play is always a bit weird, as the character suddenly "levels" into a class), I think it's perfectly viable as an optional rules module. However, I'd also like to point out that themes (I don't do 4e. are themes like kits from 2e?) do a lot for creating the kinds of character history that you're talking about. Themes, as presented in 4E, work best when they say something about your character's role in the world. Themes are something we want to be a core part of character creation in the next iteration of the game, chosen right alongside class and race, that adds a layer of depth to the character that we've seen great success with in 4E.
Additionally, we're looking at having the classes gradually layer in more capabilities over the first two or three levels, rather than providing a large number of class features at level 1, so that players new to the class have a short period of time to learn the basics of their class through play (but that can also result in 1st level characters that feel very "vanilla"). Experienced players could simply start at 3rd level if they want to leap right into a more advanced starting experience. (I'm sorry, but it's never right to "force" players to jump levels if they want the full game experience. Why not add the slower ability advancement as one of their optional "modules", which they seem willing to do with critical failures and injury charts)