Gordon,
Interesting point you bring up.
I actually addressed part of this just recently on another thread we had going. I will confine my answers to a "Western or Caucasian, if you must, type of Expatriate.
As I said there, I managed to assimilate quite nicely (albiet, with a lot of hard work on my part) but I had an advantage insomuch as my wife is local. This was probably what allowed me to assimilate at all. I have also pointed out that while I have assimilated, I did so knowing all along that no matter how permanent my life here may be, I know for a fact that I will not stay here. Even after 24 years I still know that I am a foreigner (from my point of view - an intruder from a local point of view) and will always be so. As an aside, I also find it much easily assimilating with Indians and Malays - possibly because they are also minorities?
As a married "expat couple", I am not sure whether true assimilation could ever take place here or in any Asian society (even if giving up their citizenship). I claim to have assimilated but even that is a misnomer of sorts because it is a constant effort on my part to try to be accepted in a local context. It is not a automatic thing for asians to accept "races" outside of their own with trust. (Please, lets not take that any further - we are all guilty to some extent or another)
Additionally, I really haven't seen Expatriate Families "try" to assimilate outside of saying Hi at the pool. The question here is why? Is it the standoffishness of the local or the superiority complex that most (not all) westerners seem to wear like a shroud or cloak?
Riversandlakes, you would have no problem in Singapore because there is no real difference between the two countries (most people have relatives in both). And yes, this 20+ years SPR is still a foreigner - I cannot speak mandarin, dialect, Tamil, Hindi or Malay (only english and that badly as well - I am after all an American

) This country is not conducive to total integration willingly, especially with the public housing policy amoung other things controlled by the government. If you go to Australia or the US where you live is controlled only by how much money you have to spend. It is not based on your race. This means even if I buy here I can live only where there is a spot where the 2% (Others) are available to buy. (Again, this is another subject but does impact on this discussion). As long as the races here do not have EQUAL rights to live where they see fit, then as a 2% minority I can ever feel "at home". (I know the reason for this, but it doesn't make it any more right - only pragmatic from the local perspective)
As far as the school systems being different, yes this is a problem, but so is moving from Europe to the US or vice-versa. All these are changes to routine, but the problem is much deeper than that.
The way I see it (I am probably wrong here but it is my view) is that Europeans (including the US, Aus, NZ & Europe) are predominantly caucasian. Singapore is predominantly Chinese. Therein, to me, is the difference. What I mean is Chinese, while most assume is a race (it is not), carries a heavy cultural burden. Caucasians on the other hand is a race and NOT a culture. In fact it is many and varied cultures. So while we may all look similar (caucasian) we are vastly different. This long history allows us the ability to accept most anybody (assuming we are not coveting their lands)

I am not talking about racists here - they are in all cultures) But, throw out that wildcard and we will generally accept anybody and are more that willing to meet half way. In other words, we generally come across as approachable (while in our own countries).
The other problem is that Expatriates are, unknowingly, the cause of their own problems for the most part (both eastern and western expats). We are NOT ambassadors of our countries and without knowing it (subconsciously) we erect walls to protect us due to our own insecurities while in a foreign land. This is how all the stereotypes come about. British with their Stiff upper lips, Know-it-all Americans, and Loud, Belligerant Australians. These are all facades we put up unconsciously to protect ourselves. I used to very much dislike Australians when I first came to Singapore (the only Ozzies I ever met were here) They were as I just said. It was worse when they got drunk. Then I went to work in Australia for 6 months (Cairns, Darwin, Perth & Broome). It was like they exported all the riff-raff to Singapore. The people there are great! Why? There they are in their own environment so they do not need to protect themselves or put up a front. It changed my whole attitude about the people of that country. It also changed my perspective of all expatriates in general once I understood that they may be suffering from the false facade syndrome as well. Sure made a difference to me.
sms