At the Amiganoid 2011 event held on 17th of September 2011 in Essen/Germany, the MorphOS team were present and demonstrated the latest development version of MorphOS on PowerBooks (among other HW). During this time they also released the news that version 2.8 is "cancelled", and instead MorphOS will bump up to v3.0! Among the news is also a now official announcement of support for Power Book laptop computers from Apple.
Here is a MorphOS developer's comments on the issue:
(Link)
Also, it won't be released before December.

Congratulations for the users of this Amiga operative system, Amiga you don't forget!