Back to the box: Around back, the Steam Machine's PC heritage is on full display. If this I/O panel is at all representative of final hardware, we can safely predict that connectivity will not be an issue:

PS/2 keyboard/mouse port

Two USB 2.0 and four USB 3.0 ports

HDMI, Dual-link DVI, and DisplayPort

S/PDIF digital optical audio out

eSATA

RJ-45 Ethernet port, plus connectors for the external Wi-Fi antenna

3.5 mm audio in/out, rear speaker, c/sub, and mic ports