Agree with Kevin, and am puzzled by skye's comment that it 'should' be this or that way (unless you're a prescriptivist, skye). Once can bellyache all one wants to about how people 'should' pronounce or say something, but the plural-Euro game is already settled in English usage, and it's "euros".
It's hardly difficult to see why, if you look at the analogy to practically any other currency that has a name in English that yields itself to English-style pluralization: dollars, marks, franks, swiss francs, pounds, drachmas, rubles, riyals, shekels and so on.
But words that look sufficiently 'foreign' or similar to exceptions in English may take no plural: zloty (zloties looks wrong because it loses the 'y', zlotys looks wrong because we don't like -ys plurals, so we just leave it alone), yen (looks like men? plus, the value of the currency is such, that we hardly ever have occasion to talk about it in the singular, so 'yen' already 'sounds' plural).
There is no such problem with Euro, and if you took a hundred (AE) English-speaking children of three or four years old, pointed to a stuffed rabbit and said, "This is a 'euro'. Now there are two of them--I have two ------," I'm convinced that every last one of them would say "euros". (Free dinner in the city of your choice if anyone tries this out and proves me wrong. Pretty sure the outcome would be the same in the UK, but I'll wait to hear about that.)
This plural is very compelling to a native English speaker, and no amount of blather from official publications is going to change that. If they wanted a no -s ending, they should've called it a 'eury' or something (Russians would've loved that...)