Mariza is a far better Portuguese singer (at least she was raised there), but then a fado singer for an event like Euro 2004 would be a bit depressing (though perhaps appropriate for the Portuguese national team, sad to say).
I still can't help but be annoyed with Nelly Furtado to begin with. Not long ago she was copping some "I'm an oppressed people" angle because of the dearth of Portuguese people in popular media, etc. Yeah, right. I'm sure the Canadian government will come through with reparations for you soon, you pathetic whiner.
For that reason alone, if I were Portugal I'd ban her from Euro 2004 for pretty much being an insult to all its fine citizens.