Well, I'm one of those who has said that there have been good video game movies already. A good number of them actually. While one can look at "Street Fighter" or "Dead Or Alive" a better place to look is say at the FIRST "Mortal Kombat" movie which did well enough to actually get a (terrible) sequel, and actually spawned a pretty successful soundtrack as well. Tomb Raider also managed to do well enough to get a sequel, and there are others. I think people tend to mostly focus on the horrible failures rather than the successes (which is why they continue to be made), plus it's become hip for gamers to hate on video game movies irregardless of whether they deserve it or not.
That said, I think this movie can at best hope to be average. The reason being that most fighting games have a general concept followed by a total lack of resolution where pretty much the "hero" depends on whom you play, and reality/resolution is dictated by that same choice when you win. In some universes like Tekkn an "official" victor is decided after the game (usually one of the corperate Japanese guys fighting over the company) and to set the continueing story for the sequel. This relegates a lot of the mythology generated by other backrounds and endings to filler and creates as many questions as they answer.
It should be noted that Tekken has a relatively decent storyline as far as such things go. The basic concept being rooted in 1980s/1990s fiction before the "evil corperation" had become quite as much of a stock villain, and we hadn't seen dark corperate apocolypse futures around every corner. The basic premise being similar to "Enter The Dragon" with a corperation more powerful than most nations with it's own military forces and such (ala Shadowrun or Cyberpunk 2020) holds an "Enter The Dragon" type tournament to lure in great fighters for potential recruitment into their military forces. This premise of course being weak because since every character in the game is potential a hero (or anti-hero) all of them are portrayed as having "exceptional" motives similar to a martial arts movie hero, and are usually not there for the reasons the tournament is supposed to be about (a ton of money, and potentially a high profile security/private military job, OR according to some definitions the right to request a boon of the CEO if you defeat him... one character entered the tournament to get him to build an Amusement park). The lynchpin for many character stories though is that the rules of the tournament make the "champion" the current CEO, which means if you get to the final round it's a way to face him in combat and "accidently" kill him. When otherwise he could be anywhere in the world, and virtually unlocatable, or in a bunker surrounded by an army of doomsoldiers. This being used (plotwise) as a lure especially in Tekken 6 for the CEO to also draw out their enemies and also see them disposed of (either in person, or by other competitors... perhaps hiring assasins and such to fight in the tournament for that purpose).
As a Dark Future fan, I can sort of "see" Tekken as a concept. But you'll notice they also told a lot of the story through Beat 'Em Up modes and such at the same time.
Generally speaking to really do a "Tekken" movie I'd think the Tournament set up they have in that preview will actually work against it, since to tell a decent story based on the series the Tournament is actually just one element of it, and should feature in the movie, but if they try and base the movie around it at best it's going to come down to the choreography and probably be ranked as "average" compared to similar movies like "Enter The Dragon" or "Blood Sport" which featured luminaries like Bruce Lee or Van Damme (who was a real world class martial arts champion).
Nothing in that movie really struck me as being definingly "Tekken" other than having fighters that looked sort of like the characters. What's more without getting into the actual world and the "Dark Future" techn-thriller type backdrop, suddenly sticking things like Ninja Robots out there are purely WTF worthy. You'd expect something like that in say a Cyberpunk 2020 game, and it makes sense that one might be involved in corperate plots like this, but really that movie does nothing to really establish the setting from what I saw. You don't have all of the corperate stormtroopers running around, and the points about how quite obviously the goverments of the world rank about as well agains the resources of Heihachi as they do against say Genom (Bubblegum Crisis), or Renraku (Shadowrun).
Of course to some extent I'd also say that ironically I think that like many Dark Future stories Tekken is simply too deep to do as a movie.
Still, I'd imagine it will be a tolerable kung-fu flick. A lot of tmes I get into the mood for deritive stuff like that, and I think this is going to wind up on athe quick fix list of action movie fans. Right up there with say "The Quest" by Van Damme, not great, but one of those perfectly stereotypical movies that gives you what it should in exactly the right (predictable) doses and sates the need to see people jump around and kick each other in the face.