Hi,
I am currently not aware of any plans regarding a version of Prism for JavaScript in the near feature. You can find the pattern & practices team's current road map in their web site:
As a side note, I believe you could also check another pattern & practices project namedSilk:
Silk is a guidance for developing single page applications usingASP.NET MVC and JavaScript. Although it does not have a custom framework,Silk provides guidance about several topics like pub-sub patterns, modularity, etc, as well as a reference implementation application portraying them that could become handy when developing web apps using the aforementioned technologies.
Regards,
Damian Cherubini
http://blogs.southworks.net/dcherubini