Palin sent a message that her daughter was shameful, and that lying is better than the truth.Not only Troopergate would fit such a pattern. Also, herthat she opposed federal taxpayer funding of Alaska's "bridge to nowhere." (i.e. here and here)
Even if one could excuse this behavior as a misguided effort to protect her family, what happened next is beyond the pale. Knowing full well the truth, Palin allowed the false version of this story to be used as part of a PR campaign to dupe voters into viewing her in a completely false light.
What this says about her is that she believes that when you get into a situation where there might be public embarrassment, the best thing to do is lie (apparently, the same thing she did with Troopergate).
Update: In a new post, Andrew Sullivan blogs "Here's a photo that looks like it confirms Palin's pregnancy. . ." Supposing the allegations are false, were are right back to square one.