If you judge the game's stealth on the merits of other stealth games I can see why one would come away feeling like Dishonored lacks the systems and mechanics that make other stealth games great.
But when taken in context of the game, simply stealthing through isn't the goal. The goal is conquering the environment and eliminating the target, and you have such a wide variety of creative options and methods for navigating these excellent levels that I judge it on a different scale. That isn't to say I "forgive" some things, that may be present in Deus Ex, or Syphon Filter or MGS, but rather that you don't need the freedom and extra stealth mechanics when you have the super powers in Dishonored.
I wouldn't go back and play DX and think "Man this stealth is pretty bad. I can't even become a rat to crawl through that drain pipe!"
The most important thing is that the levels and the story are conducive to your creativity and intelligent use of the games mechanics, and in that regard it passes with aplomb. While what made DX great isn't quite present in Dishonored, what makes Dishonored great is absent in games before and will likely be absent in the coming years.
