My colleague Steven Savage weighed in on the anime-to-live-action adaptation problem, which he sees as being dominated by five issues.
#1 and #2 both revolve around something that most anime fans know but don't want to accept: anime fandom is still very much a niche. Its cultural artifacts don't have the same deep, pervasive presence in American (or Western) society as do Marvel/DC/Disney/etc. Consequently, you have to work that much harder to get anyone who's not a fan to care about them — and the audience that's going to be shelling out for tickets is almost certain to be 90% non-fans or more.
That said, this is not impossible. Just thorny.
To that end, you have to find something in the material that doesn't need too much explaining. Consequently, #1 can be eclipsed almost entirely by #2 if you're smart. It's up for grabs how many Fullmetal Alchemist fans there are as opposed to Game of Thrones fans, but FMA has enough "hooks" (alchemy! supernatural WWII vibes! steampunk!) to make it salable to audiences that have never heard of the Elric Brothers.
#3 is malleable depending on the level of fidelity you keep to the original material. One of the reasons I clamor for a Vampire Hunter D live-action movie is because the stories in the series are almost entirely self-contained. There is a larger mythology, but the individual adventures can be appreciated more or less as-is. You can basically pick any story in the series — the first is as good as any — and work from there.
This is exponentially tougher if you're dealing with a series that is one giant arc. FMA comes back to mind: that's the kind of franchise where you have to tell the whole story, no matter how long it takes, or you might as well not even bother. But I suspect it's become incrementally easier to deliver such a thing if you can shoot the whole series back-to-back and finance it creatively.
#4 backends into #3. Again, D: if you make one self-contained movie and it's a hit, you have over a dozen other plotlines from the series to mine for future installments. If, on the other hand, you make one giant movie arc, that's pretty much it, unless you are really confident in your ability to extend on the work of others. The only other way you can get more money out of such a franchise is to put "From the director of..." on the one sheets and cross your fingers.
#5, however, is indispensible. My short list of candidates for live-action anime adaptations is almost entirely made up of projects that don't need to be relocalized: FMA, D, Claymore, Black Lagoon, Soul Eater, etc. It does not consist of many of the projects that have already been shepherded into production, only to die there: AKIRA, Evangelion, etc. Those projects have name recognition, but of the wrong kind: they're recognized only by fans, who want something Hollywood is never going to be able to give them in the first place. It's tempting to trust the fans to be your street team, but the track record for such efforts is pretty lousy.
Well-known properties are an easy choice, which is why Hollywood consistently opts for them whenever possible. Maverick or dark-horse (no pun intended) properties need something that can be used as the focus for the project pitch, let alone the promotional campaign; the name value of the property means little when the entire fanbase is barely going to generate $10M in ticket sales. (Again, it's foolish to embark on an adaptation guided mainly by the ambition to make the hoi polloi into fans of the material.)
I don't doubt for a second that we're going to see more anime properties optioned, and perhaps filmed. There are more people doing those things who are themselves either anime fans or at least passingly familiar with the territory than there was even ten years ago. But they need to pick projects that don't require explaining to be coherent (or fun), and that can be delivered to a broad audience without going broke.