My top prediction for 2009 is the collapse of the Euro. I think it is a near certainty that within three years, the Euro will no longer exist in any real form, though its shadow may linger on.
The reason is simple: A currency is backed by a social contract ("the full faith and credit of the United States government", for instance) and there are wildly disparate social contracts within the Eurozone. As modern and emerging economies come under great stress, they will react differently according to their own social contracts -- and they will diverge, breaking the Euro. I broadly consider Europe to consist of four different social contracts:
1) Modern social democratic states: Germany, France, Belgium, Denmark
2) Feudal profitable states: Italy and Greece - ungovernable, despite being productive; little of their commerce is captured in their tax base, and their social contract is written at the local and regional level, not as a true nation-state
3) Emerging states with aspirations: Poland, Czech, Hungary
4) "Failure to launch" states: Ireland and Spain, whose economies rocketed from penury to prosperity over the past 20 years, but who are now being exposed as children of the bubble.
A rare public claim that the Euro will break apart came from Jim Rogers today; but his suggestion that it will take 20 years is lengthy bordering on the ludicrous. The Euro has only existed for 10 years; if you think it's under threat now, why would you possible imagine that its remaining life is twice its history? I think that less than half is more likely, and an implosion during 2009 is genuinely possible. I am told by a reliable source that there is already divergence in the debt terms and pricing available for different Eurozone banks, reflecting the early stages of this process. This trend is something to watch closely.
Bizarrely, having created this crisis, America may continue to benefit in an enormous theater of the absurd; there's simply no other plausible choice as a global reserve currency than the dollar in the short term, so despite our foolish and spendthrift ways, the dollar will continue to strengthen.