1) This was the real Obama. He wasn't using dramatic pauses or voice intonation. The President is personally invested in the well being of Libyans, and this came across in his speech.
2) He focused on multilateral approaches. Obama made the issue the response of the international community, mentioning a number of multilateral organizations by name in his statement. This shows that the US understands the complexity of the situation and the need for the US to keep a low profile.
3) Resonance with viewers. Obama ended his speech discussing the universal rights of all human beings. This is the rhetoric which concerned constituents have been waiting to hear. Saying that the US will be committed to "justice" is also is a standard for the administration which it will be held to.
4) Vague on policy options. Obama said "all options were on the table" but didn't commit to a single course of action. People will be looking to the White House for specific actions in the next 24-48 hours, and the Obama administration will have to demonstrate leadership on the issue.