I've been following the development of the Meteor platform for a number of years, and it is very interesting to see some of the recent changes.
The JavaScript community has in some ways caught up to or overtaken Meteor, so the Meteor folks have had to adjust.
Meteor 1.3 is the first release that really manifests the adjustments that are being made.
ES2015 Modules
The big ticket item in this release is support for ES2015 (aka ES6) Modules. While Meteor 1.2 added support for ES2015 syntax, full support for modules was not included.
This move reflects the way that the JavaScript language itself has caught up to the once unique Meteor Package concept. And it acknowledges the popularity of npm as Meteor moves toward full support for and use of npm.
Mobile Support via Cordova Greatly Improved
Meteor 1.3 now uses the latest version of Cordova (6.0.0) and on iOS now supports WKWebView for dramatic performance improvements. Hot code push for mobile apps is also greatly improved:
...wrappers detect and handle faulty JavaScript application code. It is now possible to recover from hot code pushes of broken code that previously required an application reinstall. The hot code push system is also much faster and uses incremental and resumable updates to save network bandwidth and battery life.
On the Horizon
Next up in Meteor 1.4 we expect to see an upgrade of Meteor to Node.js version 4 and MongoDB 3.2. I'm looking forward to those improvements!