Given the extreme difficulty of the Israeli government in getting 8,000 settlers to leave the Gaza Strip there is no possibility of them persuading the more than 400,000 colonists to leave the West Bank. In my opinion the two state solution has been dead since 1993 and the assasination of Rabin. In 1988 the PLO ceded its claim to 78% of historic Palestine to Israel. The Israelis claimed that such a compromise was insufficient and they needed more land, continued control over water and control of the borders. Even after the withdrawl from Gaza is complete the Israelis will still control the border with Egypt. The Palestinians can not give up more than the 78% of Palestine the Israelis controlled in 1966. The Israelis will never give up East Jerusalem whose borders they have enlarged to include a big chunk of the West Bank.
Already including Jerusalem, the West Bank, Gaza Strip and the 1948 Palestinians with Israeli citizenship there are about as many Palestinians under Israeli rule as non-Arabs (a very significant number of first class Israeli citizens are Russians of Christian heritage not Jews). This does not even include the descendents of the 750,000 or so Palestinians the Israelis expelled or terrorized into fleeing in 1948 and the 300,000 refugees from 1967. Given their high birth rates the Palestinians will soon be a significant majority in the areas under Israeli rule. The Gaza withdrawl may buy some time, but it is not a solution to the Palestinian question anymore than South Africa's creation of similar resource poor independent Bantustans was a solution to its racial problems.
The Gaza Strip and a few cities in the West Bank with little water, arable land or control of their own borders does not constitute a viable state. Black South Africans and most of the international community rejected the Bantustans as a permanent just solution to dividing the land and resources of South Africa. Likewise the Palestinians and the world outside the US can not morally accept the permanent creation of a walled in Palestinian Bantustan. An entity that would be without access to sufficient resources to physically support its population yet alone the millions of Palestinians born in exile and have no control over its external borders. A completely sovereign Palestine with total control over its borders and water resources in all of the territory of the Gaza Strip, West Bank and East Jerusalem was the minimum the Palestinians could accept. By rejecting this deal the Israelis killed the idea of a two state solution.
The fact is that Palestinians today probably form a slight majority of the population of the territory that formed Mandatory Palestine. This edge will increase substantially in the next couple of decades. Even in the pre-1967 borders of Israel, Palestinians currently are 20% of the population and they will easily reach 25% in a few decades. When a significant and verifiable Arab majority does emerge in historic Palestine the pressure to treat Israel like South Africa and Rhodesia will be quite strong in parts of Europe including the UK. Movements for divestment and sanctions will start to have some effect in some European countries.
The Israelis will be forced to make a choice at this point if not sooner. Either they can cut a deal like the South African government did and live as equal citizens in a multi-ethnic Palestine. This means that things like entrusting 92% of the nation's land to an organization holding it on behalf of "all of the Jewish People" and prohibiting its sale or lease to Palestinians with Israeli citizenship will have to end. It also means that the Palestinians in the West Bank and Gaza Strip will have to be given the right to vote in elections for a government ruling all of historic Palestine. In practice this would mean the creation of an Arab Palestine from the River to the Sea with a Jewish minority protected by international covenants. The other alternative is to attempt to continue to rule in an oppressive and discriminatory manner over the Palestinian majority. Eventually this will probably lead to a scenerio like Algeria with the expulsion of most of the non-Arabs from Palestine.
Things have not looked good for the Palestinians since the 1948 Nakba. Since Sharon provoked the Al Aqsa Intifada things have gotten even worse for a large number of Palestinians. But, in the long run by avoiding complete expulsion from their lands they have managed to gain a long term demographic advantage. Eventually the ratio of Arabs in Palestine to non-Arabs will reach the tipping point. The ability of an unpopular ethnic minority to rule over a hostile native majority in the Arab world has been quite limited in recent times.