Given that PHP 5.3 has reached end of life ( http://php.net/archive/2014.php#id2014-08-14-1 ) I would suggest putting some checks into the Dashboard advising users that they should be getting their hosting upgraded to PHP 5.4 or higher.
It should be clear to the user when the support for PHP 5.2/5.3 will be dropped.
It should also be clear what it means; how this might affect them.
Perhaps also something about the highest level of PHP on which WordPress is supported / has been tested.
Did you really mean 2015?