time for amber2 branch?

In looking at the gallium tree, I'm wondering if it isn't time for a second
amber branch to prune some of the drivers that cause pain when doing big
tree updates:

* nv30
* r300
* r600
* lima
* virgl
* tegra
* ???

There's nothing stopping these drivers from continuing to develop in an
amber branch, but the risk of them being broken by other tree refactorings
is lowered, and then we are able to delete lots of legacy code in the main
branch.

Thoughts?


Mike