A new strategy towards Pakistan Al Qaeda?

There was another apparent US missile attack that hit an Al Qaeda/Taleban target inside Pakistan, the second in a month. It's difficult to draw a trend from two points, but do these more frequent US actions signal something?

Is the US picking off targets as they become known (off new intel) or does this represent a fundamental shift in the Pakistan/US burden sharing? Or maybe the US is picking off all they can before Musharraf goes away?