Actually, I was thinking this might be possible.

@Pain:
Yes, it saves your stats online, but it saves your armory and config offline.
Specializations is part of the armory. Sure, the CE you've put into it may be online, but maybe not...
So this may be possible.

I definitely won't be the one to test it, as I don't feel like having to work up to the gold/silver stars for a 3rd time, but I still think this may be true.

Not the trophy part though. Those are linked to your PSN, and this being an online only game, you're always on PSN when you get them, so yeah...