A quick look at Google Trends for PHP Frameworks brings up some very interesting interpretations.

If we take worldwide search frequency as a proxy for new adoption, Zend is getting stronger with every passing day. Other popular PHP frameworks are also gaining momentum but Zend seems to be clearly ahead of the pack. News reference volume, another solid indicator of media and adoption interest, also marks Zend as a clear winner.

Now, why is this important for the PHP Community?

Historically, one of the biggest challenges for early adopter companies has been a lack of commercial platforms that back a technology or framework.  Zend has changed this situation.  As a commercial operation, it has been able to create a solid infrastructure of framework, tools and certifications to create momentum around the platform.

This clearly means: more power to Zend and more power to PHP open source adoption.