Zerohedge has been doom and gloom for years yet the world keeps turning and it is business as normal.
They've been the only source of real economic and trading news in the financial sphere that isn't afraid to show how the debt is ballooning, all over the world, and the 'characters' that have put us there.
They've become so popular, a recent server move/upgrade was performed in the last month just to keep up with all the traffic. As for particular claims of when the market is going to meltdown, sure, there have been plenty of contributing articles that don't hit the mark.
Try lurking for a while, you'll see what is on target and what is pure speculation. Overall, the information available trumps anything on the internet for finance, bar none.