Hey did the quick search thing and got nothing for this thread, so I'm gonna guess it possibly hasn't been brought up. Post Hardcore group, Hawthorne Heights is currently releasing material through their own label, Carboard Empire since leaving Wind Up Records. They released their first EP, Hate, back in Aug 2011.
You guys were able to nab another group similiar to these guys lately, maybe you could hit them up too?!
dlcquickplay.com/user/shottyslankin
[ ] Cold
[ ] MOAR The Used
[ ] New Found Glory
[ ] Sevendust
[ ] Saliva
[ ] The Color Morale
These have probably been posted already, but since you guys are into the whole prog metal thing and have been relatively successful in getting bigger name bands:
-Haken (Though there would be a lot of "[song] part II", though)
-The Dear Hunter
-Pure Reason Revolution
-Kevin Gilbert
Just a few prog artists I'd kill to see. Keep doin' what you guys do, mang.
Most wanted bands for DLC:
The Protomen|Queensryche
Moar:
Ayreon|Rush|Devin Townsend
Powderburn, I talked with their guitarist about it and he said he would be willing if someone contacted them, but he doesn't believe me when I say they can get their songs on the game as easily as I explained it.
Here is a link to them