ND is currently a 9 seed based on The Bracket Project, a good site for one-stop bracketology shopping. Interestingly enough, the other 9 seeds are all from the Big East: Louisville, West Virginia, and Villanova. The Irish received a 6 seed from Build a Bracket, but were left off of Jerry Palm (last updated 2-16).
The choking sound you hear is coming from Clemson. After starting the season 17-0, the Tigers are in danger of missing the Dance with 2 wins in their last 10 games. Sitting at 35th in the Pomeroy rankings, two slots ahead of ND, Clemson made only 17 of the 26 brackets tracked by TBP. If the season ended today, they are in line for a 12 seed. Good luck getting that much with road games at Boston College and Virginia Tech still on the plate.
Note: If the link doesn't work, type in "http://bracketproject.atspace.com/comparison.htm"