I'll add that once you remove him (but where he can still see everyone) you should go back to the hurt child and give a lot of sympathy. Talk about how he is hurt and all that. Often the child bitten just continues on playing after the biter is in timeout and all seems well. Draw the attention back to someone haven been hurt. Especially if the bite wasn't severe or the bitten child isn't overly dramatic. Oh, the times I wished I could just pinch the hurt child to make them react more strongly so the aggressive child can see their friend react in pain!! (I would never do this...but a strong reaction does help)!

Allow the biter to see that the child that was bitten is getting taken care of and getting the attention and that he, the biter, is removed from what he wanted. Eventually they make the connection that they aren't getting what they want through biting. I think the firm "no biting, ouch that hurts" can help the child snap out of their likely focus of getting what they want and see what they have done and hearing that it hurts. If you just gently come in and talk about it they will still be focused on getting what they want and not what harm was actually done. You don't need to yell and scream...just use a louder voice then normal to draw their attention to the situation.