The DOJ has not filed suit yet and so there will not be any court filings proclaiming a settlement. Tonight's deadline is for the DOJ to decide whether to allow the merger to proceed or not. If the DOJ does not bless the merger, then litigation will be filed and it's a fairly high probability that the deal falls apart. If they do allow the merger to proceed, I would assume some very significant concessions that really would make one question the value of the deal. The additional amount of time is not only to negotiate concessions, but also calculate whether the deal still makes sense with those concessions. The price paid for HA was already questionably steep and would not have factored in the types of concessions that are being negotiated. They would have assumed that they would have had to keep some routes and frequencies for a period of time - they would not have factored in divesting space at SEA as others have speculated and that significantly reduces the value of the merger.