Migration to PHP5

Hi, Does anyone have stats in terms of migration from 4 to 5, specifically I'd like to know if the bulk of PHP developers have begun to change-over. I am (was) a Java developer, but have been doing freelance/consultant work in PHP for two years and am still developing on PHP4 platform. I remember when PHP4 was introduced (while I was still in college), and I made the transition to it immediately, but I have refrained from doing so for 5, since most development gigs are still working with 4. Basically I am wondering if it would be advantageous to make the switch; on another note, with PHP5's "stronger" OO model, I am considering moving from page-centric to an MVC model, but it seems there are a million MVC frameworks available and haven't had any experience with them. Comments? Christian