* Do repo need to be synced amongst mirrors?
Would be good...
Or all fetched from abf only now?
No, everything uses mirrors.
* If yes, which directory contains 4.0 repos? (i heard about rock/roll directories)
Still 4.0. rock is a symlink to 4.0. rolling is a separate tree.
* Do we still need .list files? Index of /mirrors/ or maybe we use something like mirror brain?
We can drop the .list files, but there's something else we need to keep up to date now.
It's a super simplistic script currently running on my box - that was the only thing we could get up in time for the 4.0 release.