A Petraeus Downside for Bush?

Reading Petraeus' letter to the troops, The Daily Bellwether asks:

Could that pose a problem for President Bush if Petraeus is correct and people start asking: Why were things bungled for so long? Where was the leadership in 2004, 2005, 2006? Why were we told things were going well when they obviously were not? Would the war and dying be over if the White House had recognized sooner the Pentagon and Central Command needed competent leaders?

Phil Carter is more circumspect about the import of the letter.