There are basically 2 possibilities here, and Palin comes off looking at least a little foolish in both. On the other hand, neither is a big deal.
Possibility 1: She misspoke. She knew the history, and flubbed it up as she talked. No big deal, it happens to every one who speaks publicly. She only looks at all foolish in this case because she was dumb enough to make fun of Obama using a teleprompter, then shows why they are used by every sensible politician. Basically, if this is the case, I just can't be bothered enough to care. It's minor, to make a big deal out of it is to be petty.
Possibility 2: She really doesn't understand the history she is talking about. If this is the case, she really is pretty stupid, not for not knowing her history(that is ignorance, not stupidity), but for talking in public about something she didn't know about. In the long run, if this possibility is true, I still don't care. I never figured her for being very bright, this does not change things, it has almost nothing to do with any message she is trying to present nor with any modern day issues. I and the rest of the country have more important things to worry about. Making a big deal out of this is petty.
102 posts on this so far, and none of them change the fact that in the long and short run, this does not matter. It does not change any one's opinion of Palin. It does not matter, it is nothing. This is just like threads about Obama bowing, or the NJ Gov flying to his son's ballgame, or the first lady is getting fat, or Palin painting her bus with a flag motif, or Obama taking his wife out to eat. All those threads, bitching about all those things, where stupid. Bitching about this is just the same, stupid.