This bug has been "idle" for almost 2 years, but I found a similair situation, which could make this bug much more important.
Since kernel 3.10, the "bcache" module was introduced. This essentially enables users to use a SSD disk as caching device. A sort of "storage tiering" (/ hierarchical storage management / flashcache).
If your root partition is on a bcache'd volume, the same situation applies.
If you have a bcache script in local-top (where it should be, according to the man pages), udev starts, but the bcache script is ran before the partition's device nodes are created.
Therefore, hacks are necessary, such as while [ ! -b /dev/sda1 ]; do :; done
local-top scripts should (IMHO) only be ran after udev has created all of the device nodes.