There's something to be said about going into a game with the right state of mind too. If you expect something to be inferior to it's predecessors (in these cases, typically because people are disillusioned by the inclusion or attention given to multiplayer), odds are it will suck to you... whether it's actually good or not.
Believe me, if I wasn't in the "right state of mind" in regards to UC3, they wouldn't be getting $60 of my dollars. Hell, they wouldn't get $20 of my dollars if I thought a game would suck before I played it.

Outside of certain developer interviews... where let's face it, the multiplayer needs all the talking up it can get...
Now see, with online becoming more and more prevalent, and SP campaigns seeming to take a back seat, I'd think just the opposite.
there's no reason to believe the single player won't be a grand ol' time. So why put a damper on it before you even play? 
I am sure it will be, I just hope that ND sticks to their formula that they are known for rather than looking at the SP as an after-thought to the MP aspects of the game is all.
But I guess we won't really know until the 1st.