They can choose now.
Was this a mystery before today? Is THIS what has been the missing piece in the centuries of Middle Eastern violance? I don't think so.
It was a very good speech, to be sure, but in the end, it's just more words that will probably be ignored. IF the terrorism stopd because of this speech, then I will hail it as the great piece of statesmanship that it would be. WHEN it doesn't, what will we do? That was not outlined in the speech (unless I missed it... I did run to take care of the dogs for a second). He made no promises in that vein to follow through on.
So how will some more rhetoric be regarded by the devout Jihadists? It will be ignored. This was a speech directed at the Middle East, but intended for American consumption, IMHO.