At least, we're not engaged in combat per se. Therefore, President Obama isn't responsible for violating the War Powers Act -- at least not anywhere close to the extent it's been violated by almost every modern president.
The United States in April pulled its cruise missiles and attack planes out of combat in the NATO-led Libyan mission, though it still has them on standby. It’s currently providing support such as aerial refueling, surveillance and reconnaissance, according to the AP.
The rest of this item at ProPublica is a must read.
If your definition of "hostilities" (a key word employed in the War Powers Act) is providing "refueling, surveillance and reconnaissance" to a perfectly legal NATO military operation, then okay. President Obama is all kinds of guilty. But since April, we haven't fired a shot. And April was still within the 60 day window before congressional approval was required.