The arguments against the dollar are numerous and seemingly uncontestable. The number of market "experts" warning of it's continued decline is staggering. But most people don't bother to consider the move in context and/or consult history for reference. So, consider the following chart: For example, were you aware the dollar was actually trading below current levels during the last year and a half of BUSH 43's presidency until Obama secured the lead in the polls?
The overwhelming bearish consensus itself should make you skeptical about how much longer the current downward trend can continue. If the prospects for the Dollar are so dire, the reasons for it's declining value so obvious, and the number of bears so prevalent, the current trend doesn't have much longer to run. Whether the dollar index makes a marginal new low or not is irrelevant. A long-term bottom is forming, be prepared to take advantage of it.
By the way, a strengthening dollar is not necessarily good for the US (or World) economy. Nouriel Roubini outlines his scenario in yesterday's Financial Times: http://bit.ly/neO8M