There's more than one way to buy the US$-- and buying their equities is certainly on of them. Here's the US$ relative to the Nasdaq 100 ... you'll note that both the dollar and the NDX are trending together. The A$ and the C$ relative to their principal commodities are not. This may indicate that gold bugs are trading against one another (again) without the pleasure of seeing any new players (from around the world) coming to the table.
...we could be seeing another headfake, although we're getting some excellent follow through on the mining indices, unfortunately it's still a bit early in the game to be calling this a screaming bull market and I would like to see better participation in the currency markets.