I think you just hit on a very significant point here. Almost without exception, nearly all tongues are wagging about the Bush girls. Nary a peep about Schwarzenegger's kick-butt-and-take-names speech nor the First Lady's genuinely warm and personal accounts of events of recent past.
A lot of this has to do with America's unending obsession with pop culture, beauty, a desire to know what makes famous people tick, and a need to feel important by proximal relating.