The continuation of that package PAST the 90 day freeze will be contingent upon an agreement with Abbas (even if only "in principle") on the borders. If Bibi simply sits and twiddles his thumbs for 90 days then on Day 91 Obama will declare that this "peace process" is dead and buried. He will then withdraw the incentive package and at that point he will be free to impose his own solution.
Saudis warns U.S. that 9/11 responsibility law would erode investor confidence in America (Reuters)
from the article: What exactly does Obama expect from Netanyahu?