Let me speculate on some of the numbers. My guess is The Atlantic saw a spike in hits after the election because of its blogs - updates on cabinet appointments and Obama intrigue from Marc Ambinder, which way the broken conservative movement from Ross Douthat and, probably the biggest draw, Andrew Sullivan's updates on California's gay marriage ban.TheAtlantic.com 125%
Drudge Report has probably served two functions - allowing election-fatigued readers to get links to the latest bad economic news and giving anxious conservatives a place to look for dirt on Obama.
FiveThirtyEight kept a large portion of its audience, with readers likely looking for updates on the outstanding Senate races. Silver has also gotten positive attention in the New York Times and elsewhere for his accurate prediction of the election outcome and his book deals.