Well this came out of nowhere. EPIC will be releasing all new DLC/retail release in July named All Fronts Compilation for $19.99. The compilation consists of all the previously released map packs and brings along "Dark Corners" with it. Dark Corners will include 7 new multiplayer maps and a new campaign chapter for more single player/co-op goodness.
I enjoyed, nay, loved, Gears 2 campaign mode so I'll definately be looking forward to it. The campaign add-on is intriguing for two reasons one is it's a deleted campaign, think, deleted scenes movie style not so much after-credit like continuation. The second is the press release mentions playing through the mode "guns blazing or in all-new stealth mode." It seems a bit odd they would call this "all-new". Seeing as it's a deleted chapter it seems more like "this wouldn't work pre-release so we cut it but now it does so here you go" to me, but for $20 it seems like a good deal to me.
If you already have the old map packs, Flashback, Combustible, and Snowblind, the Dark Corners content will be available via DLC for 1600 MS Points, or basically the same damn price as the retail disc, plus it comes with a strategy guide, intro video by Cliff Bleszenski, a poster and a custome live theme. Digital distribution is a bitch. Which will you be picking up?