I really loved the concept of SS2, and the first half of the game. I thought it got worse and worse as the game went on, but eh...
The game definitely had a spooky vibe going on, and hiding from the enemies did have its scary moments.
However, no game could ever compete with the nostalgia version of an old game. The version where your mind conveniently forgets that with the game's supposed myriad ways of completing various objectives, and different character types, there was one obviously best way to play, one obviously best weapon, etc. So there is much that could be improved. Maybe the psi character could be an actual working way to play the game (And not wrench simulator, as it was in SS2, at least on hard mode). Maybe there won't be a bug where if you played on hard mode, and spent too many skill points(or whatever they were called) you'd literally be stuck and unable to progress.
Now, I was very disappointed in Bioshock after being told it was a spiritual successor to SS2, so I hope they don't go in that kind of direction, and I hope they don't dumb it down too much, but at the same time, I don't want to have to go through the entire game recycling every potted plant just to have a chance to buy enough psi injectors that I can maybe use the powers I built my character around to fight my enemies, rather than whacking everyone with a wrench all the time.
So I remain hopeful, but I also want to throw a little cold splash of reality over the nostalgia filter.