PHP upgrade

I guess I’ll post this here, since it’s a general Dreamhost question. Is the PHP upgrade that was announced yesterday a security upgrade (to 4.3.10) or are there plans to upgrade to PHP 5 soon? PHP 5 will break a lot of scripts, I believe. What is the upgrade schedule?

I was upgraded to PHP 4.3.10 two night ago, so I think that was it… for now, of course.