Discussed today in the Core JavaScript meeting: https://wordpress.slack.com/archives/C5UNMSU4R/p1534251793000100
Originally raised at: Automattic/wp-calypso#26438 (comment)

An original issue was observed with @wordpress/data, where multiple registries could be simultaneously present due to independent versioning of packages having different dependencies upon the specific version of @wordpress/data.

Some observations include...

• This is not specific to @wordpress/data, and could affect anything which behaves in a global / singleton fashion: @wordpress/hooks, @wordpress/filters, @wordpress/blocks
• The issue is mitigated but not eliminated by moving away from Lerna independent versioning (toward fixed versioning) because the chance for differing versions still exists

Options for moving forward considered include...

• Avoid "globals" behavior, where a consumer must define and operate with its own registry (specific to @wordpress/data)
  • How does this work in the WordPress context?
  • Does a default registry still exist? (specific to @wordpress/data)

cc @jsnajdr @gziolo @adamsilverstein @youknowriad