I would not prioritize this much. There's a thread on emacs-devel about integrating package.el with Emacs so that it becomes very easy to install packages in a stock Emacs build so that fewer libraries need to be distributed with Emacs itself. If this happens (and it looks like the Emacs developers are in favour of it) then I think this would be a better route for Rudel to go.
Stefan has indicated that usage of the cl library would be fine for packages in the official package repositories.
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I would not prioritize this much. There's a thread on emacs-devel about integrating package.el with Emacs so that it becomes very easy to install packages in a stock Emacs build so that fewer libraries need to be distributed with Emacs itself. If this happens (and it looks like the Emacs developers are in favour of it) then I think this would be a better route for Rudel to go.
Stefan has indicated that usage of the cl library would be fine for packages in the official package repositories.