The debt ceiling has nothing to do with default (yet).
The Constitution has only one budget priority in it - that US debt gets honored first.
We collect 10x in taxes what we owe in interest on the Treasury debt.
If Treasury fails to pay the interest (a *real* default, in other words) the Congress has immediate cause to impeach the Treasury Secretary, as well as his boss. Obama isn't that stupid.
Neither are the people who seriously care about the worthiness of Treasury bonds. The media, however, has a giggling good time throwing around 'boo words', and has managed to fool some commentators.
The debt limit means we can no longer spend what we do not tax. Since 1/6 of GDP now depends on that (the 'temporary' 'stimulus' has become a structural part of current GDP), stopping 14% of other .gov spending exposes the actual state of GDP, and betrays the 'recovery' as a fake.
We've been in a contraction of >10% (a Depression) since 2008, we've just covered it up with the credit card, trailer-trash style.