One could argue that "veteran" d20 companies like Mongoose, Green Ronin, Troll Lord, etc ... have filled the vacuum that FASA, WEG, GDW, etc ... left behind.
Except the big problem I see now is that one particular game dominates the market a lot more than in the past. This is less "creative" because all you have now is variants of the same thing. I think the hobby was actually healthier when game designers created different stuff rather than altering the 3e ruleset. That's what I meant by "bio-diversity". If you let one species dominate, the ecosystem gets vulnerable to an extinction event--and a lot of these publishers took a hit when 4e was announced.
Now you're seeing a few of these guys again create their own games--they are likely not all going to use the 3e ruleset base anymore. And my hope is that will bring back the diversity we used to have.