It has test pads (not holes) on the bottom, marked PP3 (GND) and PP7 (VCC).
seen here in the bottom right hand corner (open picture in new windows to enlarge somewhat):
P.S. PP1 is VCC before it goes to the polyfuse!
So powering the PI by soldering wires to PP3 (GND) and PP1 (+5V) is functionally the same as powering the PI through the microUSB, but its possible it will invalidate the guarantee if you solder directly to the board. Also the PI isn't protected this way against reversing VCC and GND, and reversing them, (putting -5V into the PI) will immediately destroy your PI!