Our review of Tracy Smith's Open Atrium book just made it to Slashdot, confirming there is a widespread interest in this popular Drupal distribution. (By the way, the book is not, and is not meant to be, useful to developers, but if you build Open Atrium projects you should definitely recommend it to your clients: it will save a lot of time to you and them).
The most interesting consideration is that the book, published in January 2011, is still perfectly current now, as of Open Atrium 1.3 released just a few weeks ago. And this is not quite good: most distributions have been significantly updated in recent months, while Open Atrium has been quite conservative in features and updates so far.
In case you haven't heard, this is going to change. The future of Open Atrium looks bright, and, while there isn't a roadmap yet, the guys at Phase2 have recently taken steps to make sure that Open Atrium can again be a shiny example of innovation and bleeding-edge, useful, technology:
The Open Atrium Development Group is now open for everybody to join. Open Atrium is now a true community product with a transparent development process.
An interesting BoF session was held at DrupalCon Denver, where we shared our experience with advanced Open Atrium customizations and we discovered that people are pushing this distribution to many different use cases: there are hundreds of organizations and companies working with Open Atrium now, and each of them can provide valuable feedback in shaping the future version.
The discussion about Open Atrium on Drupal 7 is now open, don't miss it!