While EDH, or Commander, is perhaps best-known and most-popular as a casual format, there is, in fact, an official body of rules - it's gotten to be more and more "serious business" as it's become explosively more popular. And 2013 promises to be another big year for Commander; Theros block has something of a legendary creature subtheme, with thirteen legendary creatures (and six other legendary permanents besides) in the first set alone, and a new release of five official, allied-tricolor Commander decks with new cards is due in November.
Here's the news you're waiting for up front: There are no changes to the banned list. Commander is in a good place right now. Sure, there are some potentially unfun cards out there, but most of them either telegraph their unfun-ness, or have too much potential for awesome in the right hands to be kept down. A few months of playing with the new Legend rule suggests that it hasn't made anything more problematic. As for the current list, as a thought exercise all the RC members named a card they felt was closest to being removable from the banlist. No card got named twice.
We are making a small change to the format. For a long time, the "Optional" section has confused people. Are they official optional rules? Do they apply on a per-player or per-playgroup basis? The goal of the section was to show how flexible the format could be and that there was no problem tailoring the rules to suit your playgroup, but we feel that it wasn't accomplishing this goal in its current form. So, we're going to replace it with a "House Rules" section where we discuss the philosophy of house rules and link to some popular/and or interesting ones other groups have adopted. If your group has a house rule you'd like us to consider linking to, please suggest in in this thread.
The main impact of this change is that there won't be any endorsement of sideboards as an 'official optional' rule, though playgroups continue to be welcome to house-rule them into existence as they desire. Originally, the sideboard rules were conceived as a way to give a little more structure to competitive playgroups, but that never got much uptake; the few people who did adopt sideboards mostly did so as wishboards, and not as the intended group decision.
The League Rule also goes away, but the new Legend rule made that irrelevant already.
Theros looks like it's going to be a slam-dunk for Commander - sets dripping with flavor produce great generals and support cards alike - so go out and get brewing!
There have been a few gripes about things like Sylvan Primordial blink locks in the community, but no backbreaking trends with any of this year's cards, some of which, even in expert-level expansions, were designed with EDH in mind. The "potentially unfun cards with potential for awesomeness" refer to things like Iona, Shield of Emeria, which, as one MTGSalvation.com Rumor Mill poster put it, shouldn't be turning one or two players in the game into spectators; she's a precision tool in EDH, not a douchey sledgehammer, and using her for a hardlock is painting a target on your forehead.
One thing the committee clearly doesn't like is the Wish cycle, which doesn't fit the spirit of EDH because you're meant to play with exactly one hundred cards and singleton. That's why their lack of support for sideboards - because EDH players say "let's play with decks, not with collections."