It's not quite the same.. we know it's not going to be an ethernet port because this would raise the cost of the system, and the system already has 2 usb ports and wireless built in.
Your thoughts would really be appreciated, and if you can confirm it t be audio or definitely not digital audio that would be great.
Other therories were that it was a firewire port, or some kind of Nintendo standard port for a reciever that would sit on top of the television.
Just thought I'd add, the controller for the system is wireless.. and Nintendo's aim for the console is to make it as cheap as possible.. I forgot you might not know much about it. There's plenty about it on Google if you're interested.