Meanwhile, those who prefer greater stability can use the Long-Term Support (LTS) releases of CiviCRM. LTS users won't be left behind in the version numbering progress, however.
You can soon download the latest LTS release, 4.☔.♈, from the CiviCRM download page. Each monthly LTS release is clearly numbered according to its star sign for your convenience: you can easily know that when 4.☔.♋ comes out, your copy of 4.☔.♉ will be two months old.
Periodically, API and schema changes may be necessary, and a new major release will come every six months, identified by the middle digit change. Currently, we anticipate releasing 4.⚜.♎ in early October and 4.♞.♈ in April 2019.
The CiviCRM developer community and core team are excited about this change, and I hope you are too. We expect that adopting this simple, systematic numbering plan will cause CiviCRM to have no bugs by January 2019.