The PC version of Dark Souls released last month with the same graphical limitations that choked the console versions of the game, but modders have found ways to circumvent the issue.
A modder who goes by the name Nwks has released a patch for Dark Souls: Prepare to Die Edition that unlocks the present framerate cap of 30. The update is in alpha stage and its creator has noted that it might cause a couple issues, but if you're tired of splitting headaches from sluggish framerate then you'll be happy to know that your solution is finally here.
It's disappointing that modders have had to do the dirty work of From Software, but at least PCs provide the flexibility for solutions. The imposed framebuffer cap was equally as eyebrow-raising, but was quickly fixed by a different modder within hours of the game releasing.