Blizzard announces they've upped the experience bonus in Diablo III to 100% for this last weekend before the release of the Reaper of Souls expansion for the action/RPG sequel:

This is it! We're unleashing Diablo III: Reaper of Souls™ for Windows and Mac on March 25. To celebrate—this weekend only—we're doubling down on the +50% Bonus XP that's already available in Diablo III, and boosting it all the way to +100% Bonus XP.

This +100% Bonus XP period ends on Monday, March 24 at 12:01 a.m. Pacific Time. So, (if you need to) update your Diablo III game files here, log in this weekend, and rack up some last-minute Paragon Levels to aid you in your upcoming crusade against death itself.