I have no opposition to including the metric system, and especially in scientific articles. But in many articles, Americans will have a hard time understanding unless English equivalents are given.
en.wikipedia.org is not us.wikpedia.org. I am not an American or even a native English speaker and I read the en.wikipedia a lot, for many different reasons. en certainly should accomodate US idiosyncracies, but not to the confusion of a more broadly defined target audience.
The right thing to do is to introduce Wiki syntax for formatting units, so that they can be converted on the fly. SI should be the default.
Regards,
Erik