The Daily Wishlist Giveaway begins today on Steam. Each day 10 people will win the top 10 games on their wishlist!
To enter, you must have a Steam account and a Wishlist with at least 10 games, and each day you will need to visit the gamepage of the featured daily deal. The Giveaway begins December 1st and will continue into the holiday season.
The featured daily deal today is Terraria at 75% off!
Good luck!
Source: http://store.steampowered.com/news/6905/
10 people each day will win their top 10 games on their wishlist as prizes (as long as they at least check out the daily featured game's page), while it seems like this is the Steam winter sale.
How convenient that today's deal is Terraria, and today is Terraria's largest content update (v1.1). Perfect timing in so many ways.