Does it happen in other games or just halo 2.
Blue Static in the blacks is usually the predecessor to full on GPU meltdown which will show you weird pink and green spotting on all the 3D elements on the screen.
like this:
http://pictures.xbox...puglitch/01.jpgThe only other possibility is massive interference...
the way to tell the difference is if there is a blue spot on something and it moves with that object on screen it's probably the GPU if the spot stays on the same areas of the screen then it's likely a cabling issue.
if the "static" only effects 3D elements and 2D elements (hud, menus, etc) are fine then it's likely a GPU issue.
i used to get blue static stuff like that now and again in crackdown , but it was only in shadows, i put it down to a bug
that screen looks pretty messed up man.