I tried hold off seeing the trailer till I saw Iron Man 3, but then I heard the words 'loki' and 'curly hair' and I couldn't help it (Tom looks good with short and long hair). Anyway, this is really funny.
Since all their hair is getting longer movie by movie, it leaves you wondering where it'll be once Hemsworth and Hiddles have done their last times as Thor and Loki *strokes imaginary beard* I so love all their ever growing hair ;A;
Typically they're pretty long and then after they fuse them to their hair they cut them to the length and style they need. Then after awhile they fall off naturally, or they can just cut their hair back to normal.