I'm not saying it will, but it's possible. Mostly depends on Capcom's decision when to announce MHP3. If they announce it too soon, it won't stop selling, but the weekly numbers will drop.

saicho and Star Scream, where's the wager?

DQ9 should sell very well but you must understand that even 4.5 million may be too high. Although this will be the cheapest DQ game yet.

Maybe Sony should announce Demon´s souls 2 at Tgs this year.

Woah, there. Demon's Souls also needs to find success in the West.

Outlawuron.

Perhaps have they announced an American release yet.
I think if they announce a sequel maybe more people will be interested which could lead to more sales for it.

They have not, but these HD games need more sales in order to get a sequel.

Although this one doesn't look too expensive.

Even Sony didnt expect it to sell this good probably so a release in Us this fall and announce a sequel in Tgs would maybe be good.

Currently the best selling DQ game in Japan is DQ7 which stands at 4.12 million. I expect DQ9 to be the best selling DQ game in Japan once it's released.

You have to consider two things.

1. The series itself is in a decline. DQ8 sold worse than DQ7.

2. The game is on a handheld and portables have lower attach rates than consoles. So, you can't expect it to do too much more than DQ8 let alone DQ7.