I have multiple keyboard layouts on my Win8 (as well as on my Win7). To illustrate that - you can go to Control Panel\Language and add another language, which could be used for displaying characters in non-unicode programs and language usually have keyboard layout (besides date formatting rules separators and all that culture specific stuff), which means you can quickly switch from one layout to another and type language specific letters =). I usually have 2 languages installed - English and Russian. And normally I'm pretty happy with en-US (US culture with MM/DD/YYYY date and qwerty-keyboard layout).
Recently I realized that en-US culture formatting is a bit confusing (TFS in visual studio applying en-US culture to date formatting and it becomes a mess, cause Russia and Australia using DD MM YYYY order for dates, not MM DD YYYY one). So I installed different, en-Au culture (and keyboard layout, that is actually standard qwerty) and removed en-Us completely. So now my system have 2 languages ( and 2 layouts) - en-Au and ru-Ru.
Here is how my default language switcher (win+space) looks when FARR is not loaded:http://i.imgur.com/TSzsHsN.png?1
When I launch FARR - en-US keyboard layout added: http://i.imgur.com/8mT0rpI.png?1
No en-US culture added, just keyboard layout. This is a bit annoying cause now I have 2 en layouts and a ru one, as a result - for switching from en to ru I have to press Win+space twice, but from ru to en - only once.
What I read so far somewhere on SO or superuser (can't find exact ref right now) - Windows, not sure is it started with W8, but I didn't run into this issue on win7, could add program-specific layout if certain program explicitly trying to call for it (or something like that, my guesses about the cause could be complete bs). So probably FARR trying to use en-US specific layout and thus Win8 added corresponding entry to lang selector. Sometimes it could be usefull ( so you can use proper layout if no english layout installed), but in some cases, like mine - it should be avoided.
It'll be great if there will be a checkbox in FARR options to enable\disable that behaviour or any other way to configure this.
If you need more details - feel free to contact me by email, (nickname) at gmail com