The way I see it is a cliffhanger leads to continuation of a story, not a crappy end to one. That's just me though.
Only if it's done right. The perfect example is God of War 2. THAT was the cliffhanger and I was so f***ing pumped for the next one.
This one not only finishes the story of the main character, it kills him abruptly, and scrambles to set something else up. This was supposed to be a straight trilogy. If they wanted more, there was an EASY way to do that. The Assassin/Templar war is obviously huge. There's no way one small cell of Assassin's would finish it. And they go from there. But they didn't. Instead, we get this heaping pile of s***.
I am prepared to use this: http://www.youtube.com/watch?v=RFZrzg62Zj0&feature=related