We've all heard the drunken whaler song but will there be a full score?

No information on that as of yet.

No, the whole game will be dead silent except for sound effects and voices.

Limbo seemed to manage. :>

Well there was a bit of music, but it was mostly just a soft humming or eerie choir with the dart scene. I thought it did a good job of making me feel depressed, in a good way.

From what I can make out in the current gameplay videos, Dishonoured sounds like it'll have a really good soundtrack.

I hope its like mission impossible theme song over and over and over, that would be great

Thankfully no. And that is way overused.

http://www.audionetwork.com/production-music/the-assassin_33743.aspx

It will be amazing. From what I've heard of the in-game sound and what emphasis they've had on it, the game will have an amazing OST.