They did not "lose" on Flash. 99% market penetration[0] is not losing. I doubt they'll "lose" on HTML and CSS any more than they lost on Dreamweaver, they'll simply pull an Autodesk[1] and target the education and training market. It's hard to beat the Flash IDE for ease-of-use, and I imagine their new HTML-based product(s) will be the same.
By that metric, Java has 73%, but I basically never encounter a Java applet on the web (except when digitally signing my taxes) and increasingly hardly any Flash.
Let's talk about trends: what is the outlook for web browsing on smartphones and tablets? How big part of these support Flash? What part of those supporting flash actually have it enabled?
[0]: https://www.adobe.com/products/flashplatformruntimes/statist... [1]: http://students.autodesk.com/?nd=download_center