Known as "Ryu Ga Gotoku" in Japan, Yakuza no doubt took much of its influence from the country's gangster epics – many of which were directed by the famed Takeshi Miike. If you're a fan of the genre at all, you know who he is, and if you're not, there's a chance you've run across some of his movies in the action/foreign film sections of Best Buy or the rental store.
It seems that Miike was impressed enough with Ryu Ga Gotoku. Check out his praise: "When I heard about this, I played the game and cried twice before clearing it. We're filming with the belief that it would be great to make a movie that matches up with the game. This movie can, of course, be enjoyed just as a movie, but we hope to make the content truly interesting for those who played the game."
That's quite a pedigree for SEGA's game (which, by the way, comes out next week!).
Ryu Ga Gotoku is currently scheduled for a Spring 2007 release in Japanese theatres and I imagine that if Yakuza does well over here, it won't be long before an English-subtitled version is in the works.