The US dollar is at multi year lows primarily due to the massive liquidity infusion since the dot com implosion. This is now just beginning to reverse. Long term I am a dollar bull. The press likes to harp about the twin deficits, but that really only affects the dollar's value if dollar investors believe that this will lead to default. At this point, no one believes this. The deficit ratio is at 2%, about average. The numbers keep growing, but so does GDP. Recession fears do not affect the dollar much long term cause if the US goes into a serious decline, so does everyone else. Regardless of what the press might have you believe, the USA is still the economic engine of the world. Yanks are the ones out there buying everything. Asia is heavily export dependent, and even Europe is to a lesser extent.
Trade deficits don't hurt the dollar in the long run either. Econ 101 says it should (PPP and all that), but export countries have to prop up the $ to keep their economies humming. Sure, they could screw America big time if they just refused to buy bonds, but then they sign their own death warrant, not to mention losing bundles on currently held US assets.
Chasing yield is what moves the value of major currencies more than anything else, and this is a function of liquidity.
Long term, I believe we are near the lows right now. Especially vs the pound and commodity based currencies.
Just my 2 cents,
Jay