The most alarming claim is that the Palestinian Authority was aware of the impending attack on Gaza in 2008 - and this claim is certainly consistent with the tenor and flow of other issues in the documents. I haven't seen all of the documents but the gist of them seems entirely congruent with the actions and conduct of Abbas's Palestinian faction - and it is this congruency which will be the most telling factor not only amongst Palestinians, but in the wider Arab world. The degrading of Gaza would, of course, suit Abbas politically because of the systematic weakening it would bring to the rival Hamas authority - but if the claim of his foreknowledge is true it would appear to consitute a perfidy on the Authority's part which will shock the Arab world. His denials are quick - they have to be - but the tide of opinion in this matter may well prove to be against him: it certainly strengthens the Hamas position enormously.
If the papers are authenticated, then clearly the intention was for Abbas to position himself politically, with the benefit of a weakened Hamas, and to sell this deal to the Palestinians on the back of a carefully orchestrated campaign to win over public opinion. It is unlikely now that any deal along these lines can be revisited in the near future given the damage that has been done to Abbas's personal authority - and presumably the intention of the leaks was to scupper the talks: so the likely candidates for leaking the documents has to be a hardline Israeli who wished to see no quarter given to Palestinians; or a Palestinian dismayed at the extent of concessions being proposed by Abbas's team.
It is a great pity that peace talks remain stalled in the Middle East and greater pressure from the West - in particular from the US - needs to be brought to bear on the Israelis to bring them to the negotiating table with a greater sense of purpose and a resolution to do what is right, but it is always satisfying to see the worst kinds of skulduggery amongst politicians exposed to the public glare! Who leaked? It hardly matters: the truth only damages those whose conduct is dishonest. In this case Mahmoud Abbas appears to be exposed as a ruthless and self-serving man.