The lights are on
I, for one, am putting all of my hope in the direction the multiplayer takes. There hasn't been an amazing assassin-like multiplayer experience since Splinter Cell: Chaos Theory on the original Xbox, which is my most memorable and exciting online experience to date. I even rate it above my endless hours spent on Halo 2.
Basically, if it's multiplayer is that of Chaos Theory or more, it's a first-day buy for me. If not, I'll rent it eventually.