Matthew Weir O'Phinney has a new post on his blog today talking about overloading arrays in PHP 5.2.0 using the magic __get and __construct functions.

Several weeks back, a bug was reported against Zend_View that had me initially stumped. [...] Basically, __get() no longer returns a reference and returns values in read mode, which makes modifying arrays using overloading impossible using traditional methods.

He gives a code example of the problem and two ways to get around it - one using a switch statement to get around the problem and the other ("best solution") was Matthew's option to extend the ArrayObject class.