"No one is complaining and it was legal."

I would say that outside of the US, reactions have been very mixed and less than jubilant. Pakistan in particular has given out some very mixed messages, including threats of "disastrous consequences" if the US were to attempt any more unauthorised unilateral military raids of like kind within Pakistan. Those sound like fighting words to me.

In any event, as to the issue of legality, I believe that question is still open. The UN have requested full disclosure of details pertaining to the raid from the US:

"the norm should be that terrorists be dealt with as criminals, through legal processes of arrest, trial and judicially decided punishment.
Actions taken by States in combating terrorism, especially in high profile cases, set precedents for the way in which the right to life will be treated in future instances.
In respect of the recent use of deadly force against Osama bin Laden, the United States of America should disclose the supporting facts to allow an assessment in terms of international human rights law standards. For instance it will be particularly important to know if the planning of the mission allowed an effort to capture Bin Laden."

http://www.ohchr.org/en/NewsEvents/Pages/DisplayNews.aspx?NewsID=10987&LangID=E