Many [claimed] that Awlaki was a mostly innocent preacher – peripheral to AQAP’s attacks.  However, Abdulmutallab’s confession [in the memo] clearly ends the debate on Awlaki’s role. While I agree with some of the arguments for increased transparency, improved planning and limited use of drone operations only in the presence of clear intelligence, I have no delusions that the U.S. can wait indefinitely to apprehend terrorists like Awlaki while they continue to plan repeated attacks to kill Americans.

Me too. But more transparency is vital and I'm glad we got some more. Adam Serwer is more cautious:

Since al-Awlaki is dead and the government remains tight-lipped both about the legal justification for targeting him and the evidence regarding his role in Al Qaeda, it's impossible to objectively evaluate how reliable this information actually is. 

Marcy Wheeler picks out some of the more interesting details from the memo.