MDB2 2.5.x and PHP 5.2?

From MDB2 2.5.0b2 to 2.5.0b3 (including MDB2_Driver_mysqli), a dependency on PHP 5.3.0 was added. Is this a "hard" dependency, i.e. does MDB2 take advantage of PHP 5.3 features or is it just not tested on 5.2.x? From some initial tests, 2.5.0b3 seems to work fine with 5.2. Notwithstanding the ongoing move to 5.3, I imagine that there are others like me who will have to use 5.2 for a while yet, and it would be a real shame if we can't use any future versions of MDB2 - or have to force PEAR installs. (Somewhat related - another major change in this version that may affect upgraders is a BC break for PHP4 compatibility and some derived classes - http://pear.php.net/bugs/bug.php?id=17858 ) Thanks! Tim