Anywhere from 1.75 - 3 million long term on PS360. PC version will have much better legs. I am pulling these numbers out of thin air but that is the point. 

Game looks great. If they get the pacing right with mix of action and more slow areas. This could challenge Bioshock or maybe not. Remain to be seen. 

Bethesda has done the first Q&A regarding Dishonored. I will post the link into the OP but I will summarize the most important here.
It will take 12-14 hours to finish and for explorers the double. There will be 6 major powers and 4 enhancements. Additional you will have the chance to 40 bone charms which will grant you small supernatural perks.

yeah i read this magazine always when i'm on toilet. they like it pretty much.

I'm going with my guts and say at least 1.5 mil for the PS3 and 3mil for Xbox 360 

BTW im I the only one who thinks the skeleton mask looks kind of sad

almost every Magazine does so far. These guys have developed Bioshock 2, this one can´t be bad.

It looks melancholic in a cool way.

My most anticipated game now.

Sadly it's an under-the-radar game for many gamers. I believe it will get good reviews but not sell that much. I'm thinking 85% Meta but hoping for 90%.

I would compare Dishonored to Bioshock and Deus Ex Human Revolution to get an idea of its sales potential.

Bioshock got amazing reviews at Meta 96% and went on to sell 3.5 million on PS360. But Bioshock is Bioshock,becoming a huge success and instant classic.

Deus Ex got a 89% Meta and is on track to sell 2.5 million lifetime on PS360. But remember that Deus Ex had much more pre-release hype than Dishonored has got.

So I think Dishonored with a 85% Meta will sell 1.5 million lifetime on PS360.

Well if they advertise it properly, then maybe it will manage to hit the million on both Platforms. I mean Rage sold almost 3 million copies and this game sucked. But it got properly promoted.

Bioshock and Deus Ex succeded because of the quality.

Yeah, quality, that's why I compared them because I think Dishonored will be quality too.

Yes, there are quite many mediocre games who are easily able to sell 1 million on both platforms. But Rage I think was mostly picked up from the bargain bin. It's been 10 Euro here in Sweden for several months which means they really really overshipped.

But do you really think Rage sucks? I am playing it right now halfway through and I like it so far. Some things in it piss me off though, like the linear levels and invisible walls and the game holding your hand assuming the player is a moron.