Notebookcheck.net has published a benchmark report testing Dishonored on various mobile graphics cards:

http://www.notebookcheck.com/typo3temp/pics/b710dbe5ff.jpg

http://www.notebookcheck.com/Benchmarkcheck-Dishonored.83307.0.html

Interesting, the Intel HD Graphics 3000 and HD Graphics 4000 perform better than I expected them to.

Yes, seems quite playable at 1366x768 with the integrated laptop graphics. In this case, they tested each card with the default FOV - I wonder if increasing the FOV is a bit more taxing on the graphics card?

That's the case for Skyrim, so I can't imagine it'd be different for Dishonored.