Back in March I stumbled across a link to what looked like a beta of the new FamilySearch Family Tree and took some screen shots before the link disappeared.
Here is the post: http://enduringlegacygenealogy.blogspot.com/2011/03/familysearch-family-tree-leak.html
There are 2 other posts talking more about the same thing on my blog in March. At the time, I had no word from anyone officially what that was all about.
Yesterday, my fellow GeneaBlogger, James Tanner, posted about this beta: http://genealogysstar.blogspot.com/2011/10/beta-test-of-familyseachs-family-tree.html
Evidently, a document about this beta was released in April to a select few: https://help.familysearch.org/kb/guides/en/The_Case_for_Our_Tree_FamilySearch.pdf
There is a feedback page on FamilySearch.org for the beta:
http://getsatisfaction.com/familysearch/products/familysearch_family_tree_beta
As James Tanner mentioned in his blog post, FamilySearch likely does not give more information because this process is in the development stage. Betas for FamilySearch are known to sometimes last years as in the case of version 1 of new.familysearch.org which is now being moved to FamilySearch.org in the form of this beta.