I know Ubisoft are just the publishers, but you guys should at least have contact with From Software. So, any news on offline co-op yet? The game's been out in NA for over a year, and the box indicates co-op mode in offline play (at least for the 360). It would have been nice to have when friends come over. Or, has From Software forgotten about this altogether?
PS The forum link on your main page for ACFA (http://www.armoredcore.net/acfa/) is kind of outdated since http://armoredcoreonline.com is no longer there.
If the 360 version states this on the box then it must be in error.
If you have a PS2, then there is Armored Core: Another Age to give you some off line co-op. However, it is rather simple and there are not many missions.
Maybe Armored Core 5 will answer your hopes and dreams
Armored Core 5
like all the other AC games the offline is only VS. to play missions you need to people online.
VS. is at the start menu under multi-player then split screen
I know that where I live, having offline co-op specified on the box, but not actually an option, qualifies as a violation of fair trading laws. Under the heading of "false advertising" - if someone was willing to take it to court, then they'd have to either patch it to support offline co-op, or refund anyone involved in the lawsuit, AND recall and repackage every copy of the game that's still on shelves to remove the mention of offline co-op on the box.
Might want to check your local laws and see - patching this in would probably be a significantly less expensive option than going through court and losing (because they would lose if you have civilised laws about companies making false claims)