On the one hand I was pleased that Bethesda hired a greater number of actors for Skyrim than they did for Oblivion. On the other hand I felt, overall, that the quality of acting was a little worse. It's as though they had the same budget for voice acting in both games and were forced to hire cheaper actors for Skyrim in order to hire more of them.
And people blamed the celebrity voice actors for Oblivion's problems (Well, there are a couple in here, depending on how much of a celebrity you consider Max von Sydow to be). I thought Sean Bean in particular was pretty good... then again, Sean Bean could read the tax code in a monotone and I'd be enthralled, so that's not a very good objective measurment.

And, of course, there's Wes Johnson clearly having fun with his job.
To be fair, though, Skyrim's voice acting has its decent moments; unfortunately, like all the voiced Elder Scrolls games it suffers from repetition over and over so much you want to shove an arrow in your
knee ear to make it stop. I'm just disappointed that the voice actress for the female Dunmer (Linda Kenyon) apparently didn't return, though the new one is at least fairly close.