AMD is getiing off the ATI brand name in favor of using AMD name. The company cites internal research for brand renaming, but basically surmises that AMD brand name is stronger and better recognized than its ATI counterpart. Also, the subcategory brands of Radeon and Fire Pro have solid consumer awareness without ATI name being attached to them. The brand switch also reflects some internal changes at AMD. Many important ATI employees have been relocated to AMD's base of operations in Austin, Texas in order to help with Liano, Ontario, and AMD's future Fusion products. So the line between AMD and ATI has been further blurring for some time.
To go along with new brand we get new logos. If OEMs want to display a badge without AMD brand, there's an alternative for that as well: