In case you are interested in Windows Phone 8.1 developing, you can download the latest Visual Studio 2013 update here:
You should notice two facts:
1) It’s not a final release yet. You are unlikely to encour in bugs, but that’s not impossible at all.
2) In case you had already the Preview installed, you can just run this and it will install with no issue at all.
What changed? You should tell me, really 😉
This is what I noticed so far. You can easily add virtual buttons into emulators, to check out how they look in your app!
Happy coding! 🙂