Currently the world and/or universe targets can be used to fetch upstream downloads, but will only get the version based on the current MACHINE/DISTRO settings (following their PREFERRED_VERSION). We need a mechaism to pre-populate downloads for all combinations (if possible).
This is a little challenging since we need to know all the possible machine configurations. It might be easier to write a script so accomplish this
I am closing this one out, because 3222 has more details than this. *** This bug has been marked as a duplicate of bug 3222 ***