Sadly, I don't think that will be the case. Otaku gamers are usually Day 1 buyers. The less hardcore might wait a week or 2 but after that, games targeted at the harcore demographic usually drop like rocks.
I agree that with good press and work of mouth some other people will be convinced to buy this game. But there are already many used copies available and I think they will buy those. That's another problem with hardcore games. The players finish them so damn fast and resell them to buy more games.
It is rare to see games like Mario Kart DS, Monster Hunter 2G, Wii Fit, ect. being traded in. Those are the game that people feel like keeping. With less used copies people are often forced buy buy new ones. This is why these games continue to chart week after week. When a used copy IS available it is often only few hundred yen less than a new copy.
The used Otaku games on the other hand often go for half price or less in as little as a month after release. There is a copy of FIre Emblem at famicom dojo (the little game shop in my town) that is at the store about half of the time. It has been bought and resold to the store several times. He offers a really good rate (about 75%) buyback on games so people will get it play it, beat it and sell it back. He has a Blue Dragon Xbox 360 bundle as well that has been through about 6 owners. Only the first sale ever counts for numbers.
So getting back to my point, Valkyria will probably perform like the other games targeted at the core gamers. It will not seel much beyond its first month but in the end it will probably be played by about 3x the number of people who bought new copies. Its not so much that Japanese gamers hate good games its just that unless they have very strong reasons to get the game new (for example, getting a LE version or being an Otaku) most gamers will wait until the Otaku have had their fill and then get it on the cheap.
Wow, i wrote more than though I woud there..
Does all that make sense or is it really confusing?