PHP, Apache, and MySQL (along with a few dozen supporting libraries and such) have been updated. All of these were minor version updates, so shouldn't impact much, but if you run into problems, as always, just let me know.
In the not too distant future -- that is, a few weeks from now -- I will probably be upgrading PHP from 5.4 to 5.5. As far as I know, this shouldn't be too big of an upgrade, but you might want to make sure your PHP scripts and applications are compatible with PHP 5.5.