RunicGamesFansite announced their 2011 The Legacy Mod Contest. While it is not a Blizzard fansite, the rare prize is definitely something some veteran and newcomer modders might find appealing.
The Prize is a Diablo II Battle Chest ($40-value) signed by Max and Erich Schaefer (former Blizzard North / Condor co-Founders), and Matt Uelmen (music composer, sound designer). They are currently developers of Torchlight at Runic Games.
The mod contest requires you to create a Torchlight Mod meeting the following criteria:
Mods must be submitted to the Legacy Mod Contest Entries category by April 16, 2011
Mods must affect gameplay in some way - no cosmetic-only entries. See below for some suggestions
Mods must be created by the author, not a repackaging or copying of another person's work
Contest Entries must be new, not a mod previous uploaded to our Database
One entry per person