If you plan to pick up Call of Duty: Black Ops II this week, you may want to rely on a digital service rather than a retail store. According to many users on Steam, Reddit, the Call of Duty forums and elsewhere, boxed copies of Activision's latest shooter can't be fully installed via DVD because the second disc contains data for Mass Effect 2. From what we've seen, there's no way to tell if the second disc is correct or not without a computer because the labeling is correct. So, for instance, it'd be tough to check the disc before leaving the store.
On the bright side, all retail copies of Black Ops II come with a Steam key, so most affected users should still be able to play without waiting for a replacement disc, though you might as well spare yourself a trip to the store if you're going to activate the game on Steam anyway. In fact, if you're willing to activate it through a Russian VPN, you can get a multi-language Steam copy with English support for only $30.99 through CDKeysHere (the site offers a tutorial on using the VPN and you can play with your normal connection afterward).
It's unclear how widespread the issue is, but Activision is calling for purchase information from folks who have received the Mass Effect 2 disc so the company can sort things out. The most plausible explanation at this point is that Activision and EA contract the same manufacturer and, well, someone messed up.
Interestingly, in related news, there's also a mix up with Lego: The Lord of the Rings, as some packages contain a demo instead of the full game. The issue seems isolated to the Xbox 360 and it appears that the incorrect discs are labeled as demos, so you should be able to verify your purchase on the spot.