Facebook allows usernames - protect trade-marks NOW
Facebook has announced that effective at 12:01 am Saturday they anyone with an existing Facebook account can claim a user name. They have not given much notice, so anyone with a trade-mark needs to act quickly to lessen the chances that anyone else will try to obtain a username using one's trade-mark. More details are here and here. So trade-mark owners should go here today and fill out this form - which is to preserve rights to trade-marks.
Any business that already has a Facebook page should take advantage and claim their username asap. They apparently can't be changed once you get it - so quick thought needs to go into the right name to use.
And if a business doesn't have a Facebook page - consider whether its a good idea to get one. There is a delay for a couple of weeks before you can get a username if you don't have a Facebook page now. That's intended to lessen the chances of cybersquatting.