We're not going to default. That's ridiculous.
People need to quit saying that. Obama would have to willfully default, and no president would ever do that. Default doesn't happen out of happenstance. The President would have to actually choose to default. The amount of interest payments is a small figure and is under zero threat of not being paid - unless Obama chooses to.
Now welfare, on the other hand... That's not the same as a default, but that's where the cuts will most likely come from. Unless Obama chooses to prioritize it over defense. That's his call.