Today the Commander Rules Committee, the team who oversee the health of the format, announced this month's changes to the format's banned card list. The only change announced for this month was the unbanning of Worldgorger Dragon. This change is effective June 17th, to coincide with the Commander launch parties.
The announcement came with the following statement from the Rules Committee:
We don't unban cards lightly, but it's time for Worldgorger Dragon to get out of the penalty box. It is no longer a particularly strong example of unwelcome, format-warping, combo-play style, but simply another infinite-combo piece. Those applications are narrow enough that it should not cause problems for social players, and the type of player who wants to play this kind of infinite combo isn't going to play a more fun deck because Worldgorger Dragon is available. Thus, since it's a goal to keep the list as short as possible and focused on more fun-oriented games, we believe it can come off the list.
We'd also like to take the chance to thank the folks on the various forums for their continued input and commentary to and support for the Rules Committee. The broader community has many voices, and we do our best to hear them all.
Worldgorger Dragon was originally banned due to it's part in creating infinite combos.
View the full current banned list for Commander at mtgcommander.net.