If the MLA says one space then it has changed since I was in school (~10 years ago). We were always told to use a double space at the end of a sentence and while he links to the Chicago MLA, the actual MLA website also eludes to the fact that it used to be two spaces: http://www.mla.org/style_faq3.
Yes it has changed. Note: it's changed. It's no longer correct to call Pluto a planet, and it's no longer correct to double space after a sentence. And the MLA style guide is not Solid Snake so it probably doesn't elude anything, though it might allude to some things (as long as we're being pedantic).
