Originally Posted by Dhruin 
you don't develop any core stats/skills (so, your gun aim isn't governed by an improvable skill), there is no inventory and the pace is faster.
Awww, I wish they had kept that! It's what I liked so much about SS2 and DeusEx. You didn't change the suspense all that much by allocating points, just some minor gameplay paths were different, but it was noticable and it allowed you to specialize. It couldn't have been so difficult to include stuff like that in BioShock too, now could it?
Still, I'm looking forward to playing it eventually.