The annual holiday sale on the Steam store is officially underway. It is massive and… surprisingly involved. Just about every single publisher is offering reduced prices and a ton of bundle packs, as well as a bunch of "Pack Deals" that bundle together every game from each major publisher.
If that wasn't enough gaming for you, there's also a metagame going on—each day through January 1st, a set of six objectives will turn up on the Great Gift Pile page (as of now, I can't get that link to work, but it will probably start working soon). (Update: It's working!) If you complete an objective, you get either a gift—a full game, a discount code, etc.—or a lump of coal. Coal can be amassed and traded in for gifts or saved as an entry in a game giveaway that'll happen on January 2nd.
So: A huge pile of games on sale, a huge pile of publisher bundles, and an objectve-based metagame to win more games and discounts. Valve sure does know how to ring in the holidays.
Steam Holiday Sale [Steam]