Releasing the DLC for the X-box first before releasing it to PC killed my desire to purchase them.
Not in any sort of outrage over favoring consoles, although that is a bit annoying, but more because that I had already played so much Skyrim at the point I just can't bring myself to play anymore.
I had stopped playing for quite awhile, then they announced the Dawnbringer DLC and I thought it looked interesting, so I whipped up a new game, tried out some mods and sort of prepped for it. Then waited....and waited...and waited, until I got bored with the game all over again. The fact they couldn't even be bothered to give a concrete PC release date choosing instead to give vague time frames was a put off as well.
I mean, I really enjoyed Skyrim, played the crap out of it. But the handling of the DLC was done poorly and I don't think I could put anymore time into the game even if I wanted to.