Any concerns have been erased.
Any concerns I had have been erased. Originally when I was announced that StarCraft 2 would be in 3 parts for the campaign, i figured we were going to see a short campaign and almost all focus would be put on multiplayer, which is fine, but would lead me to think less of the game. Instead the single player is huge and not disappointing.
Multiplayer is still as great as it was, but the interesting thing is the difference in units between single and multiplayer. Not all the unit you can build/use in single, are in multiplayer, leading to very different strategies between single and multiplayer.
If you are an old fan of StarCraft, you will love StarCraft 2 WoL. If you are even just a fan of RTS games, you will soon see why SC has the reputation it has. This is a must game for anyone to pick up this year and will be a leading candidate for PC Game of the Year.