Whatever comes out of multiculturalism is the result from the laws of physics anyway and must happen.
Cultures comes and goes, there is no need to stand in the way of change. Why artificially preserve something that isn't strong enough to stand on it's own?
It is the natural order for weak and decadent cultures to be changed, influenced or even disappear, you just have the let these energies flow naturally and see what comes out of it. Now we will find out.
If you artificially separate everything, bigger and bigger unnatural tension builds up, especially with the Internet.
Eventually there will be only one culture.