Black ops 2 did what other games in the series didn't do. Not only was the multiplayer ok, but the SINGLE PLAYER let us mess around with loadouts and choices with the story. While that may not matter to everyone, its still a major point to look at, because it goes to show the effort put into the game.
In order for Black ops 3 to be good, it needs to MATCH BO2's single player, it needs to do as good or even better for multiplayer maps, and of course, people are really looking forward to zombies ( which I personally didnt play much of ) so as long as that portion is good, then perhaps Black ops 3 will do just fine.
At this point though, debating that a CoD will generally be different is probably not as big a point to make. CoD is run and gun, CoD is face paced, CoD is either hit or miss. But even though I havent played since BO2, I have some hope for this one.