I was thinking of going through Dishonored before you mentioned it on another thread late.. although I just hate the thought of playing a stealthy game.. which is a shame because the game was setting up nicely from what I remember of it and very reminiscent of Bioshock I thought.. and I know the game doesn't always force you to play stealthy, but its always the best approach and you get bonuses for doing so, I just generally hate stealth games.. I find them boring.
Go for it - you won't regret it.
In some ways it does encourage stealth, but it certainly doesn't demand it - and it caters perfectly well for those who like to be a bit more gung-ho.
If you want to go all Rambo you'll still get a fantastic game. The story caters for it - so if you kill lots of people than certain things happen throughout the story, and there's different endings depending on how you play (what decisions you make, whether you kill or spare key people, and whether you kill or hide from all the guards etc.).
As you say, there's encouragement (an achievement) for being stealthy. But there's also achievements for killing a massive number of people and bringing maximum death and destruction.
I often say I'd like to replay a game, but then don't actually get 'round to it, but with Dishonored I think I restarted the story
immediately upon completing it the first time - and I could happily play it through again another once or twice (had I not sold it).