So AMD does care about Linux, hm? Good news. Can't wait to see the benchmarks. The less reason people have not to use Linux, the better.
Let's not blow this out of proportions. It's an improvement for a single game (a 3 year old game at that). While AMD provides precise improvement % for all windows titles, they only say "significant" when it comes to L4D2. This can mean anything between 20% across the board (very unlikely) to maybe 10% when running crossfired 7970s with AA and AF enabled. Besides one line from AMD, we don't really have much to talk about.