Diablo 3 - Unofficial Countdown to ???

Bluesnews has posted a short heads-up concerning the appearence of "mysterious countdown timers" at Diablo 3 fansites Diablo3.com and Blizzplanet Here's the Blues quote:

Diablo3.com and related site Blizzplanet are offering mysterious countdown timers that currently stand at 13 days and counting. It is important to note that neither site is owned or operated by Blizzard, but of course they do have some contacts there, so it seems reasonable to trust that this is somewhat significant. They're keeping things close to the vest for now, as the countdown is accompanied by this blurb: "The number of days until half the web links to Diablo3.com. But why???" Presumably we'll know the answer on May 1.