I believe a single state solution is not a solution at all, but a contradiction to both sides' aspirations. Unlike the case of South Africa, and more like the cases of former Yugoslavia, former Czechoslovakia, former Austro-Hungarian Empire, Spain and the Basks, you can't have two, or more, nationally different populations living together in good terms. I do believe that the two nations solution is slowly heading in the right direction as we speak. You see, Hamas actually drive the Palestinians closer to Israel than they wish. I think the Palestinian people start to realize that residing next to Israel is not that bad of a way to live. I think that the fact that Hamas and its leaders spent literally hundreds of millions dollars on weapons and tunnels that mostly failed, shows that they can't be the solution. On the other hand, If the Palestinians can guarantee to stop all terror attempts, they will enjoy Israel's and the world's financial and infrastructure support. Just so you know, most of the tunnels that Hamas built are made of Israeli concrete that was sent to the Gaza strip in order to rebuild it after the 2008 operation.
Sadly, I believe the current conflict was unavoidable due to Hamas's persistence to harm Israel, even if that means hurting the Palestinians even more.
Even more saddening is the fact that the current conflict strengthened the rightist radicals in Israel, and more people than I would like started to support their views. It is a natural and frightening phenomena, but it happens everywhere in the world, much like what happened after 9/11 in the US.