NB: I've continued this with longer-term analysis that makes much more sense for investors.  Though this information is still relevant to those looking for a proxy to trading the futures, this information is much better suited to investors looking for an ETF oil hedge.

    Though my primary computer is unfortunately out of service, I've managed to run some numbers on the big four oil ETFs - Claymore MACROshares Oil Up (UCR), PowerShares DB Oil (DBO), United States Oil (USO), and iPath Goldman Sachs Crude Oil (OIL). 

    These numbers are done on a time series from Jan 05 to Apr 23, and although they're short and only provide 4 contract lifespans, I thought it was important to provide a window into the newer PowerShares DBO's behavior.

    This is not restricted to the contango trouble zone, but it looks like there's a pretty clear tradeoff here.  You can get a better relative match to spot if you're willing to take more of an average premium in average difference.  The size of the premium also has a near-perfect correlation with lowering risk, so it seems worth it for those interested in oil exposure (maybe not for those interested in an alternative to trading the futures).

    When my part finally arrives and I have a decent computer again, I'll dump the new PowerShares fund and take a look at a longer history of the remaining three (especially USO and OIL), as well as the contract rollover weeks in detail.  Although I personally expect to see the criticisms overblown, I do believe that there might be rollover performance factors that would make one fund more attractive than others for investors with certain objectives.  The numbers will tell, or at least help!