Well, here's my 2 cents, for what it's worth.
Prince of Persia:
Jake Gyllenhaal is miscast. The first time I saw him as PoP my first impression was "Jake dressed up as PoP for Haloween". In the rest of the pictures I've seen I simply see Jake Gyllenhaal, not PoP. Maybe it's better in the movie rather then in still shots, but for me he doesn't really become the part rather then stay the actor.
So who should have been cast?
Someone ethnically correct would have been nice. But from reading this thread, even those who argue for this are not sure what a Persian looks like. For most people Persian=Arabian=Iraq/Iran probably.
So we get nominated this guy:
Physically he fits the part, he has the right bodyshape. Ethnically he's not actually Persian, but he'll fit in with the Persian=Arabian=Iraq/Iran/Indian-can-get-away-with-this-look-too.
Now, I haven't watched Lost, and this seems to be the most commonly used picture of the man, but, he doesn't do it for me as PoP either.
His face has this hang-dog quality to it, he doesn't seem hansome enough either.
Them someone suggest this fellow:
Hey, that's more like it! He has the physique, the rogueish good looks, and arguably the right ethnic background. And, he's hot!
But... he's an unknown.
"A summer blockbuster popcorn movie with Hrithik Roshan" does not have the same ring to it as a "summer blockbuster popcorn movie with Jake Gyllenhaal".
There are more movie goers then videogame players, so it would be safe to assume that a lot of people will go and see this movie for the sake of seeing a good adventure movie, rather then to see their favorite video game adapted for the big screen.
For the larger audience, Jake Gyllenhaal will be what draws them into the cinema. They won't care if the casting is ethnically correct, or even if they main actor remotely resembles the video game character.
Besides that, going with the Persian=Arabian=Iraq/Iran train of thought: at the moment it seems a lot of people feel Persian=Arabian=Iraq/Iran=Islamitic=terrorist=us vs them.
Having the main hero being of arabic background wouldn't sit well with a large audiance because at the moment, they are considered the bad guys.
(not that I agree with that myself, but it is a thought that's out there.)
As for the Legend of Aang, Avatar the last airbender:
When I first read Aang was played by a white boy, it didnt' seem right. But when I look at the pictures and the videos released, I have to admit the actor does resemble the cartoon character a lot. He has the right feel to him, unlike Jake Gyllenhaal in PoP.
The same with Sokka, he has the same curved mouth for example.
Katara seems wrong to me, she's too pale and too wishy-washy. She's a Michelle-Trachtenberg-lookalike-kid that Holywood seems to like so much, but that makes her unfit for the part. To play Katara she'd need at least a tan, and a bit more spunk. They should have recast her. Unlike PoP, where thi big name is ment to pull in the audience, here every lead is an unknown, so she at least could have well been more etnically correct.
We don't know who auditioned though, this may have been all they had to work with?
Neither movie is historically acurate, both are fantasy. It would have been nice if the actors cast were etnically acurate though.
Hopefully one day there will be a big enough pool of wellknown actors to pull from when a different etnicity then Caucasian or african (or African-American) is called for.
But for now, Holywood casts what the mayority likes to see, and they still believe the mayority likes to see white actors (or Will Smith) in the lead roles.
