I might be a bit biased (we're happily using Dart in production at https://www.blossom.io) but:

I see more and more people I know who've been on the fence earlier to actually start to play around with Dart recently (last few weeks).

Why?

Improved Dart support for IDEs apart from the Eclipse based Dart Editor:

    * IntelliJ Webstorm/IDEA:  https://www.dartlang.org/tools/webstorm/ & http://plugins.jetbrains.com/plugin/6351
    * Sublime: https://github.com/dart-lang/dart-sublime-bundle
    * Chrome Dev Editor: https://github.com/dart-lang/chromedeveditor

The platform itself is also maturing quickly. Some notable recent things from the top of my head:

    * Soon: Dart on App Engine: https://www.dartlang.org/cloud/
    * Polymer.dart (replacement for Web UI, interop w/ Polymer.js)
    * Angular.dart (now 6 times faster! http://blog.angulardart.org/)
    * Dart became an official ECMA Standard (http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-408.pdf)
    * More and more incredible packages to use on pub http://pub.dartlang.org/packages?page=1
    * Dart 1.6 soon to be released which supports installing pub packages globally (similar to npm)
    * People start to learn about functional reactive programming and Dart as great native support for its concepts: https://www.dartlang.org/docs/tutorials/streams/

Building and releasing non-trivial projects takes some time so there is always a bit of an incubation period re visibility of adoption and like I said from my own perception even though it is just a personal anecdote Dart is getting picked up.

Shameless plug: I've also started a series of posts on why I fell in love with Dart. If you're interested to learn more check it out:

https://medium.com/why-dart/why-i-fell-in-love-with-dart-1f8...