How do an editor change editing language? There's an option in the bottom of the navigationpane that sais "Show All Languages". But nothing happens. I've enabled both swedish and english on my site
I'm assuming you mean that you have enabled both Swedish and English in admin mode. In which case you need to ensure that you have the uiShowGlobalizationUserInterface option in the episerver.config set to true so that you can access language settings. Then you need to make them "available languages" for your site, the same as what you did for CMS 6. Unfortunetly this option is a little hidden.
Aha, thanks. It's the "site"-tab i was looking for. But is there any indication somewhere what language you're actually editing for the moment?
Also, if I change language below sites, I get a completely different pagetree. How do I publish a swedish version of my existing english page. Like language-branch in previuos CMS-versions
EDIT -> Added question regarding languagebranch
Currently there is no indication in the UI of which language you are editing. This is something that we are aware of and we have a user story regarding language management in the UI that I believe will be developed and released in the next UI version.
In terms of viewing an English page in the Swedish site. You can do this by enabling the Show all Languages option at the bottom of the page tree under the cog icon.