One of our OfficeSpot 2.0 customers was eager to use his OfficeSpot 2.0 installation as OpenID provider. As the Zend Framework already provides all the needed infrastructure, at was very easy to implement this feature. We backported this feature to our last stable release and our customer is happy now.
All users of Tine 2.0 can be happy too! You just need to be brave and check the latest development version from svn. All not so brave people just need to wait until the next milestone release or until the next stable release.