I wouldn't trust buz when it comes to monetary matters. If he can't understand the constitution (and buys into the conspiracy theory about income taxes, iirc).
I've never heard of the amero, but the quick reading I'm doing now suggests that it simply won't happen. Canadians don't like the idea of a single monetary union (they would have to adopt our monetary policies), mexicans (at least Vicente Fox) do, and americans have probably never heard of it.
At any rate, unlike the euro, where you have France, Germany, and Great Britian{abe*} all being relatively equal in terms of economic output (2 trillion GDP(ppp), 2.8 trillion, 2.1 trillion), Canada, Mexcio, and the US are nowhere near close (1.25 trillion, 1.35 trillion, and 13.8 trillion, again, GDP(ppp)). Europe also has, at least Western Europe, a similar economy. Canada, Mexico, and the US has disparate economies with quite different ideas as to what's best (and different realities for what's best). Not only is that an massive obstacle, the USD has a ton of advantages that could be lost or weakened by adopting a new currency.
Put simply, there is no reason the US would give up the advantages it has with its currency (which is actually gaining ground against other currencies, especially the SEK, where it's now one whole crown stronger than a month ago, or moving from 6.6 SEK-USD to 7.8 SEK-USD).
Read up on it on wiki.
{abe*} I forgot that Great Britain is not part of the EMU (euro). Silly me. Still, the EMU is spread over a region where there is no single, completely dominating economy.
Edited by kuresu, : No reason given.