There is news that one of Khaddafi's sons and three of his grandchildren were killed in a NATO air strike.
I'd guess there will be pressure on NATO to halt all attacks on the city of Tripoli.
UPDATE: Here's the first report.
Oh, and if I'm unclear, I think the pressure to halt NATO attacks on Tripoli will work. Countries only reluctantly signed on to the war will argue that air strikes on Tripoli don't contribute directly to protecting civilians in rebel areas and that the risk of further collateral damage by hitting Tripoli is too high.
UPDATE: If, as I think, NATO stands down from attacking Tripoli as a result of this, the whole alliance waging war on Khaddafi's regime could unravel. Needless to say, killing a son of Khaddafi and three grandchildren without destroying the Khaddafi regime will guarantee that Khaddafi will seek revenge.
NATO and coalition leaders had best double the guards on their children and grandchildren. It's open season on leaders' relatives now.