We won't be there to see but it won't happen not in 1000 nor in 10000 years
This utopian leftist fantasy is against human group psychology. And no, I don't like it
It's irrelevant whether any of us like it or not. What is relevant is what genetics tells us about human history. There is no "pure" population. The Georgians, as people of the southern Caucasus, are a mixture of Near Eastern farmers who moved to the Caucasus (who were themselves a mixture of "Basal Eurasian" hunter gatherers and hunter gatherers from another human lineage, which then admixed with other hunter gatherers from yet another human lineage (ANE), and which lineage, by the way, has some correlation with a component present in south Asians.
On admixture runs of more recent, drifted, autosomal components, look up the Georgians:
https://docs.google.com/spreadsheet/ccc?key=0ArAJcY18g2GadF9CLUJnTUdSbkVJaDR2UkRtUE9kaUE#gid=2
In North America, in terms of Europeans of varying backgrounds, it's a total mishmash. I've said before that in twenty-five years you practically won't be able to find an American who is of 100% Italian descent. (Among fourth generation descendents of Italians, no more than 8% have exclusively Italian ancestry.That doesn't mean that part Italians don't identify as Italian-Americans, of course.) Even Jews, famously endogamous for 2,000 years, are marrying out at a rate of about 50%. If you don't want your children to admix with people of another ethnic group, the U.S., North America in general, should not be your first choice for emigration.
http://www.timesofisrael.com/why-is-jewish-intermarriage-the-highest-among-all-us-faiths/
http://www.levyinstitute.org/pubs/wp312.pdf
As for inter-racial marriage in the U.S., "Interracial marriages in the U.S. have climbed to 4.8 million (1 in 12 marriages) in 2010
[3] as a steady flow of new Asian and Hispanic immigrants expands the pool of prospective spouses.
[5] In 2010, 15% of new marriages were interracial.
[3] In 2010, 25% of Asians, 25% of Hispanics, 17.1% of blacks, and 9.4% of whites married interracially.
[3] Of the 275,500 new interracial marriages in 2010, 43% were white-Hispanic couples, 14.4% were white-Asian, 11.9% were white-black, and the remainder were other combinations.
[6 In the northeastern U.S. for example, Puerto Ricans, who carry AmerIndian as well as SSA ancestry, Cape Verdeans, Cubans etc., and especially the women, "marry out" at pretty high rates. Unfortunately, I think there's often a "racialist" motivation to this; it's called "lightening up". Pathetic, in my estimation. On the West Coast, Chinese and Japanese Americans marry out at a high rate. In California and the southwestern U.S., Hispanics marry out in large numbers.
For African Americans the situation is a bit different. Much of their admixture (up to 25-30% European in some cases) is the result of mingling from early in the history of slavery, and less than that now.
From Wiki:
http://en.wikipedia.org/wiki/Interracial_marriage
"[t]he social stigma related to Black interracial marriages still exists in today's society. Research by Tucker and Mitchell-Kerman from 1990 has shown that Blacks intermarry far less than any other non-White group
[7] and in 2010, only 17.1% of Blacks married interracially, a rate far lower than the rates for Hispanics and Asians.
[3] Black interracial marriages in particular engender problems associated with racist attitudes and perceived relational inappropriateness.
[8]"
However, that isn't strange in situations where one group is seen as occupying a position lower on the "class" ladder. As that changes, so will the levels of admixture. Even at current rates, however, look at it this way: what will the population in the U.S. be like if there is this level of mixing for the next 1,000 years or 2,000 years even with no change in socio-economic status?
That is the nature of a dynamic society with immigration from diverse areas. I'm sure that China will remain pretty homogenous for a long time. There are how many millions of them now? Also, how many millions of Indians, and Africans? For their genotypes to substantially change would require vast amounts of admixture with Europeans, and there aren't enough of them, and they're not going to be moving to China any time soon. However, if there was some massive invasion of one area of the world by another, the rest of Asia or even the U.S. by China, everything would change.