On the Zend Developer Zone the official word about the Call for Papers for this year's ZendCon event (happening in early November) has been issued:

Join the largest gathering of the PHP Community at 2010 Zend/PHP Conference. ZendCon will be held November 1 - 4, 2010 in Santa Clara, California, and is a unique opportunity to share knowledge and expertise with the PHP Community. Attendees will include developers, architects, development managers, decision makers, core PHP developers, prominent community members, and so many more.

They're looking for sessions on a wide range of topics (not just PHP-related) including development best practices, database integration, user interfaces, deployment tools and techniques, cloud computing and real-world case studies. Sessions will be accepted up until May 6th and you can submit your ideas here.