Clarity on Freepbx 2.10

Just looking for a little clarity here. Running on CentOS 5.x and asterisk 1.8.x + Freepbx 2.9.0.x and of course PHP 5.2.10 will the upgrade to FPBX hose the system?

I’ve tried it on a few test beds and it doesn’t look very good. What are the minimum requirements on the Centos 5.x platform so I can get an idea, get it working, and write up a nice little bit on it.