Osama tape a fraud?

I hinted at this yesterday, but today Steve Soto says it outright:

Your turn. And for the record, after giving it some thought, reading some of the overseas commentary, realizing that there is no way in hell for the CIA to authenticate an audiotape that quickly, seeing the Bin Laden's latest rhetoric is different from his earlier rhetoric, and then seeing how quickly the Mighty Wurlitzer and Rove had their talking points ready that

Bin Laden=Democratic war critics,

I have come to the conclusion that the latest Bin Laden audiotape, which has been around since December but is just now surfacing, is a fraud.