For those of you who aren't aware, the EDH Rules Committee follows Wizards' official Banned List Updates in terms of timing, not content. Go to the official forum for details.
That means they've scheduled four times a year to announce official changes in the format. March, June, September, and December. There haven't been major changes since September of 2011, when Erayo, Soratami Ascendant was declared to be banned as a general, though allowed in your deck.
There's another such announcement coming a week from Wednesday, and my hunch is that there will be two changes.
First, Griselbrand will occupy that same 'can't be a general but is allowed in your deck' status. The ability to consistently draw such a large portion of your deck immediately upon resolution can only fuel degenerate, unfun, and boring games. It's not that he wins immediately, but instead, a player casts him, draws 28-35 cards, and then takes another ten minutes building up storm and mana before winning. Powerful, but not the fun social interaction the RC is looking for.
Second, I think Kokusho, the Evening Star will become legal for your 100, if still not able to be your general. There's been enough discussion and testing by the RC, and a lot of data gathered, to make that call. It's a good card, and powerful, but I think they are ready to allow this.
This is all speculation, but we'll find out on June 20.
Place your bets and stay tuned!