The readme file that is used by all plugin authors in order to be hosted on the plugin repository has been updated to include a new section called Upgrade Notice. This section gives plugin authors the opportunity to tell users why they should upgrade to the newest version. While a change-log provides the changes between versions, this extra addition provides the chance to go into more detail concerning those changes. One thing to keep in mind is that these messages should not be more than 300 characters.
Hat tip to Brad Williams.