a) A/V module is added. (Optional)
With av module enabled, and Macromedia flash media server installed,
You can add webcam and voice chat features.

Therefore your potential customers can not only READ your sales representatives but also SEE them vividly! It means you will have a helpdesk with warm smile and a call center with sweet voice, intead of some plain text communication.

(Note: Unlike the basic text chat, this module needs support of flash media server or Red5.)

b) The server performance is improved.

c) Some client and server bugs are fixed.