the economist is working with zotero, the icon in the url bar appears for individual articles (as it should, I believe).

I'd say, lacking a site translator the best option is to use the "create item for current page" button - and that does entail, as cn notes, re-categorizing articles every time (not a lot of work, but an interruption of the workflow). Duplicating references would seem more tedious, though.

In light of limited resources I would think that some of these suggestions would be low priority - anything that's a web page only (politico, realclearpolitics) is automatically categorized correctly when you use the method above.
The most important ones would be the high profile newspapers and magazines, I think wsj especially, but also atlantic, tnr, and cq.

Edit:
and given the subject-line of your post, you could obviously also try to convince those sites to become "zotero ready" by following the guidelines here:
http://www.zotero.org/support/make%20your%20site%20zotero%20ready
realistically, that's unlikely to happen in the near future for, say, wsj, but maybe politico or rcp? After all, Zt has been getting some very nice exposure in the press.