It would take a fairly colossal collapse for us not to win the division...
Not true. It would take losing a few series. Assuming no sweeps, if we lose the series to the Mets and the Braves win the series against the Brewers (both certainly possible), the lead is down to 4.5. If the Braves win the series against us, the lead is down to 3.5. A 3.5 game lead is not a very big lead with two weeks left to play.
And again, I assumed no sweeps. If sweeps come in, we could be in second place at the end of the Braves series and sweeps are not out of the question. It's not out of the question for the Mets to sweep the Nationals (if the Nationals can lose the way they lost to Ricky Nolasco yesterday, they can lose to any pitcher) and the Braves to sweep the Brewers (despite the fact that the Brewers are playing fairly well now) and for the Braves to sweep the Nationals (primarily because of the desperation of the Braves and the lack thereof of the Nationals).
Look at the remaining schedule also, the Braves have an easier schedule than the Nationals.