The conditions to get the 2008 collapse are all there only bigger : reckless doing, 0% interest rate, government manipulation of markets, heavy regulation; except this time they will probably inflate the USD to make everyone whole so the stock market may not nominally go down
Lose lending was encouraged by the FED and the government with Fannie Mae and Freddie Mac
We have exactly the same situation now with very low interests rates that create the bubble, except now it is bigger, the same that were in denied are still in denied because they are participating to the foolish bubble
This won't happen since Congress will pass an act and Fed will print as much money as needed to cover all outstanding debts. And with the newly printed dollars, the happy US treasury bearers would buy even more US treasuries.
As I stated in one of my posts above, it's not that simple--you can't just print money like that. There are a lot of extra consequences, and a lot of assumptions that everything else in the scenario we're discussing is as it is now. If interest rates triple, that already means that a lot of people are losing faith in US treasuries. If the US just starts blatantly creating trillions of dollars, all faith will be lost and treasuries will crash very hard. It doesn't matter if people have tons of extra money to invest. They'll be plowing it into investments that go up with inflation, unlike treasuries and bonds, which go down.
Of course, the other part of this is what's happening to the economy while treasuries are crashing. If it's sliding into a recession/depression (which is quite plausible), then deflation could take hold, which might make bonds look more attractive. But treasuries would likely still suck.