Heroku users have been waiting for a Heroku-native feature like this for a long time, and now it's here. Just today, Heroku unveiled their WebSocket functionality, which is currently in beta status.
There is a full serving of documentation available on Heroku's Dev Center and there are three simple application examples on GitHub: One is a Node.js app, which uses the ws WebSocket implementation, another is a Ruby app that uses the Faye WebSocket implementation (Node.js and Ruby developers should definitely check out Faye if they haven't already), and the last is a Java and Play Framework app. The Node.js application shows you a real-time map of all the client locations currently viewing the Heroku announcement post.
While it seems like this feature is long overdue, it makes sense that Heroku would take their time with the development of WebSocket functionality, given the security concerns that surround it. A cloud platform has to be incredibly careful about security.
Hopefully this new feature will mean more real-time, multi-player web games like BrowserQuest, since it's so easy to deploy these kinds of apps now.