It seems like a very hardcore niche game but people keep claiming this will be a big title for MS this year. Will it be a system seller or are people treating it as one because they are hardcore gamers and they think that if they like it everyone else will as well? To me this has a very hardcore cult following. DMC would probaly be "mainstream" equivalent of this game yet it failed to really push consoles, your thoughts?

the latter. Online every announced game is a system seller. In reality world, very very few games are.

Short answer, no.

Long answer, a little. I think sales will move up marginally the week of its release but it won't be anything significant. Less than 15%, tops.

I consider games like Gears, Halo, GT5, FFXIII, etc. to be system sellers. Console sales have to really jump the week of release for me to put it into that category.

It is more mainstream in Japan, but a niche game outside Japan. MS will hope this will have some effect on 360 sales there, as small as it is. Its not a system seller in my eyes.

hell no. most of my 360 fanboy friends havent even heard of that game.

Wikipedia cites NPD saying that NG and NGB sold around 1.5 million combined as of August '07. No, this game is not a system seller.

Considering how few people owned Xboxes in Japan, and considering the low sales of NGS on the ps3 in the region, I'd say NG is far from mainstream there.

 What? no way in hell is that true.

 http://www.gameinformer.com/News/Story/200407/N04.0727.1752.42649.htm

GI: A lot of American gamers have complained about the difficulty. How did the Japanese market feel about it? Did they feel it was just as difficult? … Did they whine just as much as Americans did?

Itagaki: Well, I’ll prove to you how closely I keep tabs on what’s going on in the marketplace. In Japan, the Japanese consumers’ number one complaint is, “If you have time to make Ninja Gaiden, why don’t you spend that time making DOA 4?” That is the number one complaint. And, of course, the Ninja Gaiden fans in Japan, they’re saying that Itagaki should only work on Ninja Gaiden from now on. So now that we have two groups that are competing and fighting all the time. In terms of the difficulty level topic since, you know, we only sold through, like, 60,000 units of Ninja Gaiden in Japan so it hasn’t been a big problem at all. Typically, the number of complaints is relative to how many units you sold.

Ninja Gaiden - 70k
NG: Sigma - 90k
Dragon Sword - 9k

Although one is a remake, and the another was on the xbox which didn't sell many consoles in Japan.  But going by those numbers, Ninja Gaiden isn't very mainstream in Japan.  Maybe the NES games were, but not now.

No it isn't, but it is a great game anyway.