Thanks for asking, Peter. The options we considered are described in detail at https://www.mediawiki.org/wiki/Universal_Language_Selector/Design#Location_for_the_selector.

When we tested the top-right position for language settings, it generated confusion for users on wikis with inter-language links. The top-right area was a new language-related area and they expected content language to be changed from there. We were never really satisfied with the UI elements that WebFonts and Narayam added, so those are implemented in Universal Language Selector.

In short, depending on the context, language selection may have different purposes:
* For contexts where the language of content can be modified, the language list will be shown by default, and the trigger will contain a list of likely languages.
* For contexts where the content language cannot be modified, the settings view is provided instead as default. Since inter-language links are not being initially replaced by the language selector for monolingual wikis such as Wikipedia, the Universal Language selector will not be used to change content language.

Cheers!

Siebrand