My impression is that most countries don't have as generous of immigration laws as the US does, and judging by the experience most of my immigrant friends have gone through, that's saying something. Have I been FUD-ed?
If you are looking to emigrate from a 'third world' (what a ridiculous term) country to a wealthier one it can be quite hard. If you already have family or friends somewhere that can make the process considerably easier.
I think it's pretty much a given that Australia and New Zealand will accept you if you (a) speak the language (b) have a profession and (c) no criminal record. When I goto the local playground sometimes I wonder if I'm not in a suburb of London, such is the amount of English accents I hear.
This is why BC and Alberta were thriving when the Canadian dollar was worth more than the US dollar and the price of oil was sky-high, while Ontario was suffering. That said, I'm not sure of the larger implications to the Canadian economy as a whole if the US tanks. It may be simple to move to trade with China, though it may not.
And that is after you get here.