I'll post a different topic for the entire NFC after MNF tomorrow, but I can now expand on Seattle's complete playoff picture now.
As a point of reference the current NFC Playoff Picture look like the following with two games to go (three in the case of Detroit)
#1 Seattle_x(NFCW) 12-2 (Div 3-1, Conf 9-1)
#2 New Orleans (NFCS) 10-4 (Div 4-0, Conf 8-2)
#3 Philidelphia (NFCE) 8-6 (Div 3-2, Conf 7-3)
#4 Chicago* (NFCN) 8-6 (Div 2-3, Conf 4-6)
#5 Carolina (NFCS) 10-4 (Div 3-1, Conf 7-3)
#6 San Fran (NFCW) 10-4 (Div 3-1, Conf 7-3)
x: Seattle has clinched a playoff berth
*: Detroit has three games to play and has a 2-0 head to head vs Chicago and thus the inside track to the NFCN title.
The following teams are mathematically alive:
Arizona (NFCW) 9-5 (Div 1-3, Conf 5-5)
Detroit* (NFCN) 7-6 (Div 4-1, Conf 6-4)
Dallas (NFCE) 7-7 (Div 4-0, Conf 6-4)
Green Bay (NFCN) 7-6-1 (Div 2-2-1, Conf 5-5-1)
For the most important part, let me do that first. Seattle's magic number (vs San Fran) to clinch both the Division and the #1 seed (HFA) is 1/2. What that means is that Seattle could TIE and still clinch (and likewise San Fran could TIE and Seattle would still clinch). That's because anything other than a loss in the next two games puts seattle mathematically out of reach of any other team in the NFC assuring both the Division and HFA throughout the playoffs. Seattle has 12 wins. The best ANY other team in the NFC can do is now 12 wins, and San Fran and only San Fran has any tiebreaks against Seattle in the event of a tie.
Furthermore because Seattle won and New Orleans lost, Seattle has been eliminated from the following playoff seeds:
2, 3, 4, 6
Seattle is eliminated from the two seed because the best either Carolina or New Orleans can do is tie Seattle, and if Seattle does win the division at 12-4 (the only way this happens), Seattle has the head to head tiebreak on both.
Seattle was eliminated from the #3 seed when Philly lost. It is no longer possible for any other division champion to force a three way tie with the winners of the NFCW and NFCS which means that the NFCS and NFCW will have the #1 and #2 seeds no matter what.
Seattle was already elminated from the #4 seed by virtue of having more than 10 wins, beyond the reach of any NFCN (and now NFCE) team.
Seattle has been eliminated from the #6 seed by virtue of having 12 wins. In order to be a wildcard with 12 wins, Seattle would have to lose out, but New Orleans and Carolina play each other next week and one of them will be the wildcard out of the NFCS. This guarantees that the wildcard out of the NFCS will have less than 12 wins.
I hope this has been useful for everyone. It's #1 seed (by far the most likely) or the #5 seed. No other possibilities for Seattle.