Presently, all three division leaders in the NL (Florida, Chicago, and Arizona) have the same record, 23-15. I don't know if this has ever happened this late in a season. it's hard to do just because teams rarely all have the same number of games played until the last week of the season.
The Marlins have yet to play the Diamondbacks or Cubs this season. Eventually, some team is going to pull far ahead of the peloton just for the sake of making my "If the playoffs started today..." sidebar much tidier.