Pakistan's Army has ruled the country for more than half its post-independence history. Besides enjoying the rush that comes with wielding power, the military's top brass has enriched itself by getting involved in many businesses, directly or indirectly, through front companies. Retired Generals hold key positions in the country, often in fields far from their areas of expertise. There is no way they are going to give up power easily.
Gilani is an unlikely Don Quixote, a Prime Minister without the strong grassroots political backing of a Benazir or Nawaz Sharif. The chance that he can make a dent in their hold on the country's institutions is bleak, to say the least. It could be that he's counting on the support of the middle class, hoping against hope that the wave of anger sweeping the Arab street will blow Eastwards into Pakistan. He could be hoping that the anger that ejected Gen. Parvez Musharaff from power is still lurking below the surface, and will stay Gen. Kayani's hand.
We will have to wait and watch, and hope that his calculations are correct.