2-3m worldwide. Gains (over Prime) will come mainly from Japan and Europe.

It's a little early to say, but my guess is more than Prime 2 & 3, but less than Prime 1... But that's just a optimistic guess. Metroid Prime 3 didn't have the most enthusiastic of advertising campaigns. Maybe with more attention than MP3, it can outsell it, but it really is too early to say...

2 mil.

1.5 - 2.5 million

2/2.5k.

There is some serious overestimation in this thread. If Metroid Prime 3 didn't even get to 2m, why would this?

Because it's basically "Metroid 5", unlike the Retroids it's going to get a big push, and unlike the Retroids the Japanese will actually buy it.

Hmm... I would want to lean toward slightly over 1m, but I think that Team Ninja may boost sales of this game some in select regions. So I'm going to bump it to about 1.5m.

I'm going to wager that it outsells MP3. The new direction will breathe new life into the series like MP1 did.