I am playing with Omega for the first time today and was horrified to discover that this popular, modern, Drupal 7, HTML5 theme, is using PHP 4 code for OOP (I teach OOP in PHP). Maybe a minor thing to you, but it's either an up-to-date theme or isn't.

The main thing I've noticed so far is lack of visibility modifiers for class members. Todo:
- Replace "var" with public, protected or private for properties (class variables).
- Add public, protected or private to methods (class functions).