Ideas:
Seas of Alleron:
Spawns bottom left and top right of the map. Possibly rotate the whole thing by 45° to make it either north-south or east-west. Deathmatch map for 2v2, 3v3, maybe 4v4?
The whole thing would play similarly to Canyon Ambush, but somewhat larger and more open.
Blistered Abyss:
Have not played it enough to be able to suggest anything specific.
Parous Glenn:
No specific ideas. I think we should focus on some of the other maps first, although there are more possibilities here for the future.
Blood Narrows:
A smaller subsection ranging roughly from C5 to G1. Spawns in the north and south, with battles happening in the various valleys
Devil's Eye:
Too open and not symmetric enough for a Deathmatch. If at all, try crazy king with a hill at each drill, plus maybe 2-3 hills in the big open area. I ranked Devil's Eye pretty low on the list though, because I don't see any good subsections for DM.
Oblivion:
Haven't really played it that much, so I have no ideas of my own. But I trust Richard's suggestion for this map to be a good one.
Sunken Reach:
Far too big and probably too open as well. If at all, it would need to be some section of it, but I do not know which that could be.
Thornholt:
In general too linear. Perhaps the area between the A and B refineries. But I would have to check in game to see if that is actually suitable.
Voyager's Cove:
I think the current PvP implementation is pretty good we should focus on some of the other maps first
Wandering Ridge:
Perhaps a large square in the middle of the map. I've only tested it once in devapp, by my general impression is that it could make for a good map for any and/or all of the modes. Sort of like Labyrinth, but more open. Although perhaps we should give it some time in PvE first, to iron out any potential issues.