We’re trying something a bit different with this release. Instead of waiting until we have a feature-complete Release Candidate, we decided to err on the side of getting the release out sooner, even though it’s still under active development.
The initial beta contains various changes that have been sitting on the
devel branch since the last release, along with the first usable implementation of the new module system.
Please comment here if you have questions about how things are supposed to work. Comment on the GitHub issue about bugs that you find, or missing features that you need.
Announcement with instructions about updating to the beta version: https://github.com/meteor/meteor/issues/5788
Specific instructions about using ES2015 modules: https://github.com/meteor/meteor/blob/release-1.3/packages/modules/README.md
Growing list of known remaining tasks: https://github.com/meteor/meteor/milestones/Release%201.3