I would love something like this, as I would like some MWLL swag myself, however other mod teams aren't under quite the same types of license restrictions we are, so I don't know if this is possible for us to do or not, as it would still technically involve us receiving monetary compensation for any product - game, t-shirt, mug or otherwise - that relies on the MechWarrior intellectual property, even if it's just the word "MechWarrior".
Great idea though.