Adobe has been demonstrating the technology for converting Flash animations to HTML from quite some time, and have over time added greater support for HTML5 to their products through addons, and extensions.
You merely browse for and select your .fla file, select a output file, and click on convert.
The tool is currently limited to converting Flash animations to HTML, and cannot handle ActionScript code. This tool is not intended to convert an entire Flash application project to its HTML counterpart, but rather as a way to convert your Flash animation assets to HTML such that they can be used in your HTML-only projects. This also paves the way for using Flash Professional as a tool for creating pure HTML animations.
The HTML files generated by the Wallaby tool can be edited using any HTML tool, and seem to be using the popular jQuery library. Although currently it seems that the HTML files generated using the tool are currently "aimed" at WebKit-based browsers such as Google Chrome and Apple Safari.