I was looking at the ODST screenies in the weekly update when I came across seven little pictures on the left side of the screen... Then i noticed they were skull indicators. So I made a list of shown skulls.
->Picture<-
From top to bottom:
Iron
Tough luck
Catch
Blind
Black eye
Famine
Mythic
I also noticed that they were all gold skulls except Blind, which is the only silver skull with a negative effect so it would make sense if they changed it to gold. In conclusion there are now only 7 gold skulls in Halo 3: ODST, meaning they removed Thunderstorm, Fog and Tilt. Also it's pretty safe to say that Grunt B-Day and IWHBYD are in there as silver skulls too =D
[Edited on 08.03.2009 12:16 AM PDT]