In brief, they say the old slogans and terms -- two-state solution, land for peace -- are impotent and should be abandoned. In the past both parties have felt they were provided solutions from third parties and asked to accept or negotiate them.
A new beginning should be made by a process that elicits anew what the essential interests of the relevant parties are--the Palestinians, including both Fatah and Hamas, and the Israelis, including the settlers. This might leads toward a two-state solution, or it might not get anywhere. What is clear, they think, is that merely polishing up the old terms, proposals, and solutions will not work.
I found it provocative and maybe even correct. See:
http://www.nybooks.com/articles/22731
