If they were truly an accurate gauge of a future candidates electability, Obama wouldn't run for reelection and Mike Huckabee would be the next President, and neither of those instances are going to occur.
I totally agree that the polls are going to move around wildly as events change. That is why I am not dismissing Trump or Palin, nor am I cheerleading them. I have such a deep hatred of Obummer that any opportunity to throw him out in ‘12 is how I will vote. I think all of this will reveal itself after two things. We see who is actually running in the primary and the first couple debates. Debates always weed out the weak right away so the focus can be on the real deals.
I have one caveat on dismissing possible candidates. I have dismissed that POS Myth Romney. Romneycare should have him at home writing books this election, not running against Obamacare.