very sensible IMO
This is great news for several reasons.
Firstly there are some great tools written in PHP that would be painful to port to Java. CMSMadesimple is a good example - brilliantly simple cms built on smarty that gives the front-end developer content management that separates content from style from client-side scripting from meta-data. That's all cool. Sure there are JSP/tomcat/whatever tools that can do the same but we don't all want to have mega-clusters as front end servers where a bunch of cheapo LAMP systems with mutiple redundancy will do. Now what if you want to integrate that layer into something far more complex and transactional - a big ecommerce system or a bank or a CRM or a workflow system that uses SAP or Oracle. Well up til now you couldn't cos PHP does it's thing and Java does it's different thing and never the twain shall meet (at least in a stateful context).
This new work from Zend opens the door. Why re-write an open source PHP project in Java? Use the Zend bridge to bridge the gap. Why re-tool a Java-based system to work with the new front-end - use this new Zend bridge to allow proper separation and sanity between the processes in the system.
PHP is great at feeding out simple stuff to make simple webpages in a fast and slightly dirty (but we love it) way. Java is full of object-oriented mystical messaging systems and queues and threads and processes and whatnot. All Zend are doing is letting them work together in a sane manner, IMHO they are to be applauded.