Today, one of the Blues made a post stating that they will be wiping the Achievements for all Beta characters during the realm maintenance.  Per Bornakk, a Blizzard poster, this will be taking effect today, so you beta testers may have to redo some things. Read on for the official statement...

As part of testing our new Achievements system, we will be wiping Achievements for all beta characters during the beta realm maintenance today. When the next update launches a number of achievements will show up on characters again but many achievements will not be saved and will have to be redone to show up as completed.

We are very excited about providing updates to this new feature and we thank you for your help in testing it.