Even if IRI is right. Nawaz Shariff has to wait for next four year to win the election. And I doubt it if he can win election in sindh, Baluchistan, Paktoonkhwa, (except in Hazara Belt). But ofcourse he can rule over Pakistan by just winning in Punjab.
They have a good shot at NWFP after the ANP screwup. Alliances with parties in Sindh and Baluchistan isnt hard, they've done it in the past. Remember, the PML[N] even the Q lota league has formed Govts in the past.