Oh, for better or worse, you can be pretty sure therell be no break between these entities whilst Arafat is alive. Fatah may have a harder time been seen as a partner in peace because of it, but as long as he's around, Hamas will stay under control, in no small part because they knew he shared alot of their views.
Israel will use it as a pretext to not negociate of course - after all, he's the man who turned down Oslo - and Im pretty sure Arafat would turn down what Abbas turned down without a blink.