r53348以降のBlenderで以下の機能が追加されているそうです。
(Blender.orgの主催者のTonさんが更新してました)
まだ、ビルドしていないので実際のところどうなのかは不明・・・・。

まだいろいろと試さないと駄目みたいな書き方なので隠し機能といった扱いみたい・・。
大規模な製作をしない限り、あまり関係なさそうですが・・・
いっぱいLinkしてる人には、役立つのかもしれないね。

---- 原文 ----
New features!

- Packing .blend files

If you work a lot with dynamic linked .blend files ("Libraries"), it's always hard to
share your work with others (or for bug reports!).
This new option packs all used external .blend files, and - on save - combines it together
in one .blend file. You can save that file on any location.

Loading a packed .blend file then loads all library data usual - not editable.

Just use unpack to save out all linked .blend files. This will only save out the files
according the directory structure as was used on linking - relative to the current .blend.
It will create new directories, so be careful with unpacking when relative paths go up.

This feature also works fine for linked compressed .blend files.

It also works for many levels deep linked .blend hierarchies.

Access is hidden for now - I need to get some people to give it serious testing first.
You can find the options via spacebar search (try pack or unpack).

- Packed data and Undo

Now all packed data is excluded from the Undo buffer storage. Keeps undo memory smaller
and makes faster redo possible.