Unfortunately, it seems that Zend has lost another developer - Chuck Hagenbuch (of the Horde Project) who worked in Zend's Professional Services team and contributed to the Zend Framework as detailed in a post on his blog.
Yes, I am leaving Zend. I felt that it was time for me to move on. It's been a great place to work. I learned new skills there, met wonderful people, and did some things that I'm very proud of. I wish everyone there the best, especially the professional services team that I am leaving.
As this leaves a hole to fill at Zend, they're already actively looking for others to come work there (see this post from John Coggeshall for more information on that).