Open Atrium 1.1 released - status Drupal 7 version
Open Atrium 1.1 was released yesterday, but it's only a maintenance/security update. Phase 2 acquired Atrium from Development last summer, and at that time announced there are no plans to port OA to D7. However, there is activity in this thread regarding a port to D7. One of the biggest blockers seems to be a missing D7 version of casetracker. Casetracker plus also seems to be a candidate but depends on the Driven API which needs porting. Another approach might be the support module which actually does have D7 release.