Mitchell failed, like all his predecessors because he was not sufficiently acquainted with the mid=East style of politics, where a word is not a word, and bargaining begins with outrageous demands. Obama's speech will have the same problems, idealistic, Western, straight laced, unsubtle threats. When Hamas releases Shalit, Israel will open the blocade. when Hamas accepts Israel and stops firing rockets, and relates to Fatah civilly, the table will be ready for discussions.
Magnitude 4.2 quake strikes near Grand Coulee Dam in Washington (Reuters)
from the article: U.S. official: Mideast envoy George Mitchell to resign Friday