I don't know a whole lot about photoshop. But at the very least, this document looks very suspicious. The video makes a strong case on how the birth certificate was "shopped." And its not like people can claim that the birthers shopped the document to make it fit their agenda, since it came directly from the white house's official website.
So what would happen if congress officially recognized it as a fake? Does everything that the president has signed become null and void? Would Obama be thrown out of office, therefore making Joe Biden president until the elections?