AMD partnered with Novell to develop and release
the initial open source driver. Many vendors that would like to sell Linux (Dell, HP, Lenovo, Acer, Asus) on machines with the option of using ATI video cards will undoubtedly be supporting with development resources or money.
The 2D specs are already out, and the 3D specs are being sanitized. This is moving much faster than expected. Apparently, AMD was working this behind the scenes for months before the announcement.