In the first Banned and Restricted List update of 2013, now aligned with each set's release, few changes were announced.
Here's the announcement from today:
Announcement Date: January 28, 2013
Effective Date: February 1, 2013
Magic Online Effective Date: February 6, 2013
Modern
Bloodbraid Elf and Seething Song are banned.
Magic Online Pauper
Empty the Warrens, Grapeshot, and Invigorate are banned.
Standard, Extended, Legacy, Vintage
No changes
The loss of Bloodbraid Elf will slow the advance of Jund as the best deck on Modern. Seething Song took a slightly circuitous route to it's banning:
Looking at the results of games, turn-three wins are frequent for Storm, contrary to the DCI's stated goals for the format. The DCI looked for a card that was very important to the turn-three wins but not one of the cards that make this deck unique. We decided Seething Song is the best choice.
Pauper's changes are more interesting, specifically taking storm out of the metagame equation. While it's a format played almost exclusively on Magic Online, it's growth has been hard to miss. Wizards has a clear interest in seeing that growth continue through this year as well.