Apparently first printed in the Spanish newpaper "20 Minutos" and now doing the rounds all over the net and the English press, I reckon it's made up but I can't find any proper debunkers. The (English) translation is:-
At the end of the sixth month of 2006,
The King of Spain will cross the Pyrenees with his army.
The legions of Beelzebub await the battle on the central European plains.
Destruction and defeat will fall on the evil-doers.
The Holy Grail will be returned to Spain.
I hope this isn't true as I want England to win it!
Hope you can get to the bottom of it.
Don't lose hope. I have searched high and low through various translations of Nostradamus' prophecies (e.g., here, here, and here), and can't find a quatrain that even comes close to matching the one you quote.
What's more, the text contains words that don't seem to appear in any of Nostradamus' writings "Beelzebub," for one; "evil-doers," for another. Nor have I found a single reference to the Holy Grail.
In short, it appears to be a hoax. Nostradamus wrote no such thing. If that isn't enough to allay your concerns, consider this observation from The Guardian: the World Cup final is scheduled to take place in the seventh month of 2006, not the sixth. Would the great Nostradamus have committed such a blunder? I think not.
For good measure, I visited the Nostradamus Quatrain Generator and used its handy "Ask Nostradamus" feature to pose the question, "Who will win the 2006 World Cup?" The answer was this:
Suddenly arrived, the terror will be great
In the path of the hollow mountains
The twelve red ones will spoil the cover
Before and after Mars to reign by good luck.
I take that to mean that some guys wearing red jerseys will win, but I'm a novice at this, I'll admit.
Update: Spain was eliminated from the 2006 World Cup in its match against France on June 27.