I know jgarzik didn't want this, but IMHO it belongs in the repo instead of (insert name of third party here)'s repo.
If the ubuntu/ubuntu ppa is to be linked on bitcoin.org (which I very much believe it should be), I would say its much better to have a debian folder in bitcoin's src, even if it just sits there and only one or two third-partys update it via pull requests instead of the core team keeping it up-to-date.
Note that this is essentially how the gitian scripts have been done for the past many releases, also just because a debian/ folder is here, doesn't mean any core devs have to deal with releases or the bitcoin/bitcoin ppa, it just makes the build process a bit more transparent and a bit more public.
Anyway, its open for discussion.