According to jashkenas/underscore#2771 (comment), these changes are planned:

1. Fix things so that development is smooth again.
2. Check existing issues and PRs for things that might be best addressed before modularization.
3. Release version 0.4.
4. Modularize.
5. Release version 0.5.
6. Complete any missing documentation and unittests.
7. Release version 1.0.