The warning is getting stronger as time goes on from about any credible investor in the world, that the U.S. dollar is on its way to crashing, and those heavily invested in dollar-denominated vehicles will be crushed if they don't get out of them as soon as possible.
At minimum, we should at least own something not denominated in U.S. dollars, and weight our investment portfolios in that direction.
Even today it was announced the Federal Reserve is going to continue to buy up mortgage-backed securities, to the tune of over $500 billion more through April 2010. That means even more dollars are going to be printed to pay for all of that, again, putting even more downward pressure on the U.S. dollar.
If you're overexposed, you'll sink along with the U.S. dollar collapse, don't let that happen to you while you still have time to change things.