He apologized a second time, and it was sincere. Palin accepted it. I don't think he'll ever make a joke about it again. Let's move on.
What's funny to me is that in all the articles I've read about this ordeal, MSM refers to Bristol as an "unwed mother." Which of course, she is. But they use it as a justification for Letterman's joke. Like - "see, she's an unwed mother; it was appropriate. The Palins are overreacting!" They couldn't just say her name, Bristol. They had to put the unwed mother thing in there, too.
What the MSM doesn't want to admit is that's one of the reasons why people were outraged. Bristol was in a committed 3-year relationship with the father and they were engaged. Are all women who have a baby in their over 3-year relationships with their significant other allowed to be called "sluts" and be the subject of sexual jokes involving spreading their legs for Alex Rodriguez during a baseball game? I know it would have been better if they got married, and that everyone got married before having kids. But sometimes it just doesn't happen and the woman in question shouldn't be called a slut because of it. I just don't think that's slutty behavior, in my opinion.
Anyway, it's over now. I'm sure Letterman won't be making those kinds of jokes ever again and we can all move on now.