It's hard to see the Impact getting any kind of result on the road against the Galaxy and they are in very poor home form at the moment, so a draw against Philly seems likely. They should beat Toronto in the season finale, which would give them 50 points for a fourth-place finish.
Philadelphia will be disappointed with its draw in D.C., but is a fairly strong road team. A draw against Montreal combined with a win against a Sporting KC side with nothing to play for would give the Union 50 points to settle into the final playoff spot (Montreal would claim fourth over Philadelphia via the tiebreaker).
Chicago hosts Toronto before visiting New York to close the season. The Fire should handle Toronto, which means their playoff lives could come down to the final week against New York.
If Philadelphia beats Sporting and Chicago falls to New York, the Fire would finish one point below the Union with 49 points and miss out on the postseason.
New England finishes the season with back-to-back contests against the Columbus Crew. It's very difficult to beat a team twice in consecutive weeks, so I'm giving the Revs a home win and a road loss to close out the season, which would put them seventh with 48 points and the final playoff places will look like this:
1.) New York Red Bulls (already clinched)
2.) Sporting Kansas City (already clinched)
3.) Houston Dynamo 14-11-9 51 points
4.) Montreal Impact 14-12-8 50 points
5.) Philadelphia Union 13-10-11 50 points
6.) Chicago Fire 14-13-7 49 points
7.) New England Revolution 13-12-9 48 points
Of course, this is all conjecture and speculation, which is why they play the games, but, boy, will it be a fun final two weeks of the regular season.