So, they finally got around to it and it’s officially here! Glad to see this happening.
http://www.archos.com/support/support_tech/updates_dev.html?country=gb&lang=en
For those that want to use build-root and create something with minimal userspace the sources for SDE also appeared on archos git repository:
(note this is the source for the content of the SDE aos file, it does not allow you to create a signed AOS file. If you want to use the output, just flash it through recovery)