Right off the bat there was a problem. My .fla Flash project files were created using Adobe Flash Professional CS4 or earlier, but Adobe warns that Wallaby will work only on Flash CS5 files. It's not kidding: The converter stubbornly refused to read any of my .fla files until I opened them in Flash Professional CS5 and resaved them in the CS5 format. But once that was done, the conversions went smoothly and took just a few seconds per file. (The converter can also be invoked from the command line for batch processing.)
Wallaby outputs clean, clever code
Wallaby's output is very interesting. The main output file for any project is an HTML5 document, and the generated code is clean and concise -- far superior to the Save as HTML feature of Microsoft Word, for example. It even contains helpful comments indicating which portions of the code correspond to which Flash symbols. Unfortunately, however, it does not validate as HTML5 per the W3C's Conformance Checker, mainly because it uses XHTML syntax where it is forbidden in HTML.
Graphic elements are output as either PNG or SVG files, depending upon the nature of the original asset. You might end up with a lot of individual files for each project; even for my simple demos, 100 files was typical. Even text is rendered using SVG rather than HTML, and it renders using system default fonts if the specified fonts aren't available.
But can Wallaby cook?
So far, so good. But while the Wallaby engineers have made sound decisions in designing the tool, what you actually get when you convert a Flash project to HTML5 is extremely limited.
For starters, Wallaby's reliance on SVG to render vector graphics means its output is incompatible with nearly all versions of Internet Explorer (with the possible exception of IE9 -- I didn't check this beta browser). In my tests, even Firefox 3.6 struggled; although some demos rendered partially, most yielded only a blank window. Chrome, Safari, and other browsers using the WebKit rendering engine seem to be the only viable targets for now, and even then a few graphic elements occasionally go missing.