While Dwayne's Israeli 'friend', who now lives in the States may be a rabidly right-wing nationalist(and I do know some right wing Israelis from my time in the States), from my experience with people I know and my understanding of the numbers, a large portion of the emigrants come from the higher educated, liberal to leftist minded stratum.
For instance in the end of the article by Huggler it has a section on "The families who returned home" http://news.independent.co.uk/world/middle_east/story.jsp?story=465406 it talks about Charles Lenchner who now moved to Washington. I happen to know 'Chad' personally for some years and he was always very active in the anti-occupation and environmental movements.
I have friends here, computer programmers who were downsized or their company closed, others who recently graduated university and can't find a job, who are leftist (the most conservative of them vote Meretz), and have no deep Zionist ideology holding them here, so they get the hell out of here any way that they can (a couple went to Europe for work, others got into grad/doctorate program and went to the US, others to India and East Asia for as long as their money will hold out).
On the other hand, none of my right-wing acquaintences plan on leaving or spending long periods of time in the near future away from Israel. In fact I have heard some say that they won't visit Europe because they are all a bunch of anti-Semites there and 'Why should I give them money after what they did in the Holocaust'. Moreover, they are afraid of India because of 'all the Muslims.' Besides these factors, many of them feel that this is the most important period for them stay to defend the 'homeland' and show 'the Arabs that we can't be frightened away.' If anything, a good number of them bad-talk the ones who decide to go. (Even from a general linguistic perspective, there is a bad connotation to the term for emigration from Israel: 'Yeridah' which means 'going down'; in contrast to immigration to Israel: 'Aliyah', which is 'going up')
Meanwhile you have French Jews (the most rabidly Zionationalist group of people I know); Religo-nationalist British, South Africans, Americans; and newly circumcised Peruvian Indians (http://www.guardian.co.uk/israel/comment/0,10551,770315,00.html), etc. who have been moving here to take up arms in defense of the promised land.
And I don't think my wife's family is contemplating on moving back to Yemen anytime soon.
Remember that it is the Morrocan, Iraqi, Yemenite, Ethiopian, Kurdish, etc. (Mizrahi) communities who demographically have the highest percentage of right-wing voters here (since 1977) and are the least likely to 'go back to where they came from'. (Russians also tend to be quite right-wing, but I am not so sure on numbers, though from my understanding many of them would probably prefer to have gone anyplace other than here, and many would go to the US if given the visa).
So, following this trend into the future -- looking at who is emigrating vs. immigrating, birth-rates by social group, etc. -- Israel's population will become increasingly uneducated, religious and jingoist-nationalist. Israel's arsenal is not going anywhere soon, and without even the paltry vocal opposition that exists now, this will not bode well for either the Palestinian or Israeli population.
If a majority of those who do care somewhat about Israel's adherence to standards of civil and human rights dissapear, I fear to think that what goes on now will appear a mere shadow to what will be unleashed.
Palestinian demographic majority or not, they will not last a minute against a population who fears their numbers, has lost any internal moderating force, does not give any thought to world opinion, and has by far the strongest military in the region.