In the interest of fairness, an Obama post deserves a Clinton post. 4 tough challenges for Clinton:
1) Release the damn tax returns already. Either there's nothing embarrassing in them, or there is, in which case don't you think we ought to know? What's in there now that won't be there in August if you become the nominee? There is simply no good reason for refusing to release tax returns for the past several years.
2) Stop trying to change the rules. The Nevada at-large caucuses were legal. The Michigan and Florida primaries do not count towards delegate count. Those are the rules, and you agreed to them, even if it was a bad idea in retrospect.
3) Enough with the made-for-McCain lines. There is a fine line between campaigning why you would be a good president versus why Obama would be a bad one, and lines like "McCain and I have crossed the national security threshold, but you'll have to ask Senator Obama with regards to his campaign" cross the line. If you want to make the case that you'd be better than Obama on national security, do it in a way that McCain can't repeat verbatim in the fall.
4) Sit down, take a deep breath, and seriously think this through. Barring a complete and utter Obama collapse (unlikely) there is no way that you will be the Democratic nominee. Are you doing anything besides giving the McCain campaign fodder for the fall?