Forward-looking statements don’t always come to pass as precisely as we expect. Our Linux support is a work in progress, and I can’t comment on what is going to appear when.
Omega driver is now available, VAAPI is supported in it, Refer release notes at http://support.amd.com/en-us/kb-articles/Pages/AMDCatalystOmegaLINReleaseNotes.aspx
Media SDK (Linux) is not available for this driver, But it does not stop you from developing applications in this driver. Kudos to Open source, There are many open source sample codes for VAAPI and full-fledged applications which accelerate through VAAPI exists which you can use over this driver and develop your applications.
https://gitorious.org/hwdecode-demos/ -> Many sample codes available here, VAAPI based decode, ffmpeg->vaapi decode
http://www.freedesktop.org/wiki/Software/vaapi/ -> Few sample codes on VAAPI
Mplayer in VAAPI mode,
GST-OMX in VAAPI mode
VLC in VAAPI
Note: You also have freedom to use Open source Driver (Called Radeon, Catalyst is called closed source), For more details on this please refer to http://xorg.freedesktop.org/wiki/RadeonFeature/