First off: don't be too eager to see a good book in VG form.
Anyone here play the Wheel of Time video game?
yeah.
the magic system doesn't exactly lend itself well to a controller.
Imagine running along, halo style, with a videogame controller in your hand. you see an enemy ahead of you, and press the "Steel/iron" button. a dozen blue lines appear on the screen. you want to pull on the one attached to the target's sword.
right now, as you are reading this, put your hands in front of you and try to imagine the complexity in the controls of trying to select a single blue line out of the dozen. would you use the stick to select it on the screen? would you use the right and left shoulder buttons to cycle through all of them?
now imagine doing it in combat, where you have a split second to burn the metals, select the thread, push the "pull" button, and react to the outcome.
this is assuming the most intuitive control scheme, where the left/ right sticks are for moving/looking, the d-pad is for burning/deactivating different metals (grouped in twos: the metal and its alloy) A/B are for pushing/pulling the current activated metal, and X/Y are for "jump" and "ready a coin"
if you can think of a better control scheme, tell me.
unless this will be made for the wii, where the point& click interface makes it natural, but you would run out of buttons to assign things to very, very quickly.
the MMORPG is pretty much right out, unless you don't mind destroying the world you've created and replacing it with one where 1/3 of the population is mistborn. do you really think the players would choose anything else? the other 2/3 would be (presumably) hazekillers and Inquisitors.
last thing: atium in multiplayer? impossible. in singleplayer, it would work a lot like bullet-time, but atium is supposed to tell you what will happen in the very near future. the only way for the computer to know that (and display it to you) is if it's just for NPC's
[edit] this might sound a bit disparaging, and don't get me wrong: I'd love to see a good Mistborn videogame, but don't be too optimistic. the magic system is incredibly complicated to convert to a playable form, and in the end, I'd rather see no videogame than a bad videogame