With the imminent release of a new OpenSRS API, I am going to hold off work on the PHP base class until the specs are released.
From what I gather, the PHP base class will remain pretty much unchanged, since the client and server still go through a similar handshaking routine. Hopefully they will "fix" the CBC encryption problem and let me use the CBC routines in the mcrypt library directly, instead of relying on Mike's "hack" class. :)
Also, with the move to an XML-based API for commands, creating an extended class should be pretty easy.
Finally, I am on vacation until the end of the month, so if you have questions or comments, you'll need to wait until then before I can respond.