I covered my shorts late in the day of the homebuilders and retailers (XRT and XHB). Late in 2009, I shifted some of my short exposure from SPY to a combination of SPG, QQQQ, XRT and XHB. Rotating my shorts was a good idea as I actually made money on them as a group, even though SPY is higher (mostly thanks to SPG). This was the last of them and now I am only short the SPY.
On net, I have slightly lowered my short exposure today by covering some shorts and buying shares of Exelon. My net short exposure is somewhere between medium and high.