I'm 60/40 on it. The 40 is because it's been so long since Half Life 2 and even it's 2nd DLC that people are going to be expecting the game to be greater than what it is. Then for the 60 that's because to me Valve hasn't made a bad game. You can dislike their games, but they really haven't made a bad game. Each game in a series improves from the last game and it doesn't remove anything or have retarded changes. Let's take a look at Halo.
The game started off with a decent weapon sandbox then in the 2nd game it became loaded with useless and half weapons. Instead of improving it in the 3rd game and with Reach Bungie kept it the same and kept adding in pointless shit just to have a weapon sandbox. I know Valve doesn't go past 3 in a series besides Counter Strike, but they still haven't fucked up anything in the newer game. Even if the game doesn't meet expectations I think it's safe to say it's going to be an improvement without retarded changes to it.