Apparently Black Ops' Map Pack 2 maps have been leaked. I was browsing YouTube to look up some gameplay on all the Pack-A-Punched guns in Zombies, when this came up in the "Related Videos" section:
Thinking this was just full of baloney, I decided to try it myself on my PS3. Turns out, it's 100% true. Go try it out for yourself. By the way, I saw this only for PS3, so I don't know about Xbox or PC.
Step 1: Go on "Multiplayer".
Step 2: Go to "Player Match" and go on your "Playercard".
Step 3: Go to "Community".
Step 4: Press Square to go to your filter.
Step 5: Go left or right on the "Maps" section It will eventually show the Map Pack 1 maps as well as the Map Pack 2 maps.
List of Maps: Cargo, Cubatown, Hotel, MPUI_ICEBREAKER, MPUI_OUTSKIRTS.
Try it yourself. Reminder that I only saw this on PS3, so I don't know if it works on Xbox or PC.