Either that, or people here rely more on word of mouth / trying the game out rather than pre-ordering games and hoping for the best. 

It has a shot at 1.3 million. I expect Brawl to tripple Melee's number. The addition of Sonic (Sonic is still popular in EU) alone will boost the launch number even more.

And if it still don't break Halo3 after PAL, there is always the China release

"Is it possible for brawl to reach this in opening week in Europe?"

Doubt it without looking at past data I really doubt that a cartoon characters from dozens of different games fight with each other game could be such a hit in Europe. Just too weird setting. (Yeah I know its great but it looks weird.)

No. Simple as that.

It likely won't beat Halo3 just off of Europe release.

But as Joeron said, there are a number of places the Wii has yet to launch in that won't get SSBB quite yet, and it can easily top Halo3 after those.

After all, the 360 is marketed to a larger number of countries presently.

Sadly, it's not gonna happen. We'll have to wait till Halo 4 or Smash 4.

 Or due to the fact that most of time the games are not released on the same day in all the European countries. In the US and Japan a launch would be consistent over the whole country, while here it may differ from one country to the other by a bit.

That's also an important factor for some games, although I don't know how many games really are released on different weeks.

If you're lucky, ioi can make a 1.3 million Euro prediction for you. He will just have to take it down should Nintendo release official figures later. That's how reliable European software numbers are, sadly. :(

I think brawl can do it. There has been so much hype for the game like Halo 3 had, but with brawl it got delayed twice when it was so close to come out. They also had a site to go to see what player would be annouced and that had to atract a ton more people! So yeah I think they can do it in one week. Just make sure they stock a ton of copies like they did for the usa release.