Two recent posts that some here may find of interest.
1. Everyone is Still Underestimating China on why current trends indicate that China will overtake the US in real GDP by 2015 & emerge as the "last superpower" as early as the 2020's.
2. Another View of the US Economy: Observations on Exergy, GDP & Median Incomes - might be porn for some of you people. Due to 1) the huge role of "useful work" as a factor in GDP growth, 2) useful work depending on (A) exergy & (B) technical efficiency, and 3) with (A) about to decline due to peak oil / lower EROEI coal and (B) flattering out due to diminishing returns to more investments into efficiency ==> the US economy is likely to go into decline.
Also, as argued in the post on China, the decline may be precipitous, unleashed by a stampede out of US Treasury bonds (which in its turn may be triggered by a geopolitical crisis).
My thoughts on these aren't fully formed, yet, but I will continue refining and posting them in the future.