Winning % based. Too lazy to convert this to Won-Loss:
Nationals-.490 (actual W%-.587)
Braves-.581 (actual W%-.547)
Marlins-.544 (actual W%-.528)
Phillies-.486 (actual W%-.513)
Mets-.508 (actual W%-.493)
So..using this method of determining W/L records, the Braves should win the division.
This also demonstrates the fact that the Nats have received a whole lotta luck in being number one in the division.