Let's release MuseScore 2.0.1 asap to fix the most serious bugs.
I created a 2.0 branch from the v2.0.0 tag https://github.com/musescore/MuseScore/tree/2.0 and I cherry picked the commits worth having in 2.0.1. I would propose to keep doing this. Master is dedicated to 2.1 development and we work on it. Then we backport fixes to the 2.0 branch for MuseScore 2.0.1 release. If you contribute via pull requests, you can continue to send PR to the master branch.
From now on, the nightly builds will also use the 2.0 branch so we can all test the bug fixes and have a strong 2.0.1 release.
If you have questions or remarks, feel free to pop onto our IRC channel #musescore on freenode.net