Last modified: 2014-02-27 20:46:21 UTC
http://en.wikipedia.org/w/api.php?action=query&prop=langlinks&titles=Main%20Page returns something like <langlinks> <ll lang="ar" xml:space="preserve" /> <ll lang="bg" xml:space="preserve" /> <ll lang="ca" xml:space="preserve" /> It should be <ll lang="ar" xml:space="preserve">blah blah</ll> This happens with every wikipedia.
All the langlinks on enwiki's main page have no title specified, since an interwiki link with no title specified happens to link to that wiki's main page: https://en.wikipedia.org/w/index.php?title=Template:Main_Page_interwikis&action=edit#. The API result merely reflects this situation. See https://en.wikipedia.org/wiki/GIGO for details.