#1 - June 30, 2011, 1:04 a.m.
Blizzard Post
We’re going to be applying a hotfix soon to remove holiday-specific bags when the holiday period ends. The specific bags in question are:

Loot-Filled Pumpkin (Hallow’s End)
Keg-Shaped Treasure Chest (Brewfest)
Satchel of Chilled Goods (Midsummer Fire Festival)
Heart-Shaped Box (Love is in the Air)

These bags will only exist while their holiday is active, and when the holiday ends they will be removed. This is to resolve an exploit revolving around keeping these bags beyond the holiday period to re-roll their contents.

You’ll want to be sure to open and remove the contents of any holiday bags before the holiday ends. If you still have any bags from previous holiday events they'll be removed when this hotfix goes live.