There is a great site, PlayoffStatus.com, that has all the odds of every team to make the playoffs in the NFL. It includes by conference, by division, has magic numbers, basically it has everything you need to know to figure out the chances of your team making the playoffs.
Here are the Giants chances at each of the six spots in the NFC playoffs and also their chance to not make the playoffs:
1 Seed – 56%
2 Seed – 19%
3 Seed – 7%
4 Seed – 2%
5 Seed – 9%
6 Seed – 5%
No Playoffs – 4%
The site also has listed the best case and worst case scenarios standings wise for each team.
The following will increase the Giants chances at the highest possible playoff seed:
Giants beat Ravens
Cowboys beat Redskins
The following will hurt the Giants chances at the highest possible playoff seed:
Ravens beat Giants
Redskins beat Cowboys
So as much as it would be nice to see the Cowboys eliminated as soon as possible, it will actually help the Giants more if the Redskins lose.
The site has all sorts of cool features and information to offer, so I suggest checking it out.