It's extremely difficult to predict the future. My heuristic is to keep majority of assets in the currency of my life so I have them in CDN. Trying to predict currency fluctuations is fraught with risk so I try to minimize my exposure.
FWIW my guess is that the USD will continue to devalue because of monetary policy and there is little to be done about it really. Eventually it will stabilize. My guess is that creditors will get sick of paper assets and start buying hard ones inside USA like Japanese did in 1980s. Partially as an inflation hedge since it's going to eat everyone's bones. Inflation should be your #1 worry always.
From what I've been reading it seems that the perception of the economy is getting better slowly. Eventually talking heads will start changing consensus and things will get rosy again. Next bubble is definitely in gold/metals/oil. The dumb money has been chasing this for awhile with gold as the forerunner. #1 indicator is mouthbreathers talking about how great an investment it is. That is when my alarm bell goes off.
If I had to have the majority of my money in USD i would put it in stocks with foreign earning power and monopolistic market to combat inflation, and inherent competitive advantage to see out choppy economic perception. Seems like everyone hates stocks still so that's a good indicator to me.