Judging from the level of demonizing anti-Gaddafi propaganda and increased military presence in the area, NATO is considering a "humanitarian" intervention.American forces should not be used for any purpose other than defense of the lives and interests of Americans. If Obama uses force in Libya for humanitarian purposes any American deaths or injuries will be blamed on him. I suspect that threat in and of itself is enough to deter Obama.
So far, the case for intervening to prevent a humanitarian catastrophe is weak. Current death toll estimates range from hundreds (similar to Egypt) to a few thousand. I see no proof of a major humanitarian catastrophe... so far. The Libyan air force appears to have only bombed military targets, not unarmed civilians despite news reports to the contrary... The worst confirmed atrocity in this conflict so far was Gaddafi's use of mercenaries to shoot at crowds of unarmed protesters.
The situation in Libya has the potential to become a humanitarian catastrophe. Therefore the UNSC should be prepared to authorize military intervention.
NATO should have a plan in place now, to act if the situation turns into a humanitarian catastrophe.
If NATO has no intention of intervening and instead plans to watch a Rwandan scale crisis unfold from the sidelines, then they should say so now and yield to other UNSC members who might be interested in developing a plan to restore order in Libya.