Much to the chagrin of the investors who were around at the time, the bond market is once again at 2007 yields, and if history is any guide, whatever comes next will be determined by whether the economy powers ahead or stumbles. On Sept. 30, the 10-year Treasury yielded 5.26%, and on June 12, 2007, it closed at the same point. Owners of the iShares 20+ Year Treasury Bond ETF (TLT +0.31%), an exchange-traded fund (ETF) of long-dated government bonds, are getting particularly stung here, since bond prices fal ...