Seems quite straightforward to me, look at the symbols near the connectors.
The display port is obviously a MICRO-dvi connector as seen on the Macbook AIR, so not a MINI-DVI like in current macbook, you will need to buy a new adapter.
The first port is a mag-safe power connector (look at the symbol), rather than a fw800 port... so - assuming the taped port on the MBP15 case is a dual FW and not an e-sata - the MB13 would lack a firewire port, this will disappoint a lot of audio pros, sound engineer, musician, etc.
The mistery hole either is the IR port, or a new magsafe power adapter, this would change all my firewire speculations, but I don't believe that.