So ladies and gentlemen, go check out the the new Iron Man 2 trailer and pay attention to the scene shown at 1:23-1:26 into the trailer. Anyone else notice the metallic coloured wires / veins around the arc reactor in his chest?

Couple things, just for clarity: 
 
-In a similar move to Nolan denying he would ever have Robin in his Batman, Favreau has stated that Extremis will not play a role in his Iron Man Universe. However, that could have been a ruse. 
 
-The triangular chest display is not solely linked to the Extremis armor. 
 
Those points stated, I wouldn't be surprised if this is a full on interpretation of the Extremis in the movie, but I doubt we'll see IM wearing a full gold bodysuit. The concept will likely have been stripped down for the film, or even to the point where Tony Stark ends up having to remove the RT from his chest, use medical technology to fix his heart, and builds a new RT setup for the Mark V (He starts the trailer in the Mark IV).

the suit in the second picture looks different than the one from the first movie. could this be a result of the first picture?

would be interesting but not yet defenityl not yet it would feel to rushed mabye iron man 3, hell they could even put the mandarin in it just make him extremis powered

Extremis won't be in the movie, Tony has had other armors before Extremis that have had the triangle on it, and the image with Tony and the arc chest unit with all of those blue vains my be that he's been wearing the thing in his chest to long, and may get his heart fixed up in this movie, and seeing the second image makes me believe this idea even more.

I actually didn't notice Iron Man, War Machine was in the way xD

a bit of a spoiler alert here. 
 
i dont know if its related to Extremis or not but the veins on his chest was from plutonium poisoning from the ark reactor in him. 
he made a replacement for the plutonium one with one made out of a new element and made it a triangle shape.

Nice