If it were Halo 3 releasing on this sort of userbase, but it's not 

More like 5 million first week. Larger install base, full blown halo game and Microsoft knows how to advertise the hell out of a game. Know need to worry.

Is that even a question? I think it can possibly do 1.5 M before noon on the first day. People will line up at midnight, and many will take off work. This is Halo we're talking about.

It'll probably sell that much in a mere few hours...

ODST did 2+ mill.

Halo Reach, the next BIG Halo game (and yes Microsoft are going to advertise it from heaven to earth)

4+ mill first week with ease.

Yeah, but do you think MS wil ladvertise this???

I mean, Halo 3 was comprehensible, it was the last instalment in the epic successful trilogy that saved the Xbox. But I don't see Reach getting this sort of treatment

I'm going to be nice and just answer the OP, since I'm in a good mood today.

Halo is one of the two strongest console FPS brands out there, the other being Modern Warfare. If Halo 3: ODST's first week sales can't tell you anything, I don't know what will.

The more interesting question is if it can beat 1.5m in Others first week

@Th3R3ach

They gave ODST the same treatment. And it was a semi expansion pack. So I think a FULL Halo game is probably gonna get the same treatment because Microsoft isn't just gonna let a Halo game slide.

I don't really understand your logic here. Halo is Microsoft's biggest franchise by far. Reach is part of the main story. This will get the blanket marketing treatment that Halo 3 received and it will result it an opening week approaching or maybe even exceeding MW2's X360's first week.

I'd be surprised if it didn't get 1.5m in pre orders alone.