... the one thing Flash got right that will never go away with browsers is that it made your application look the same in every browser on every system and also now makes your desktop application look the same on every platform including mobile ...
I respectfully disagree with this statement.
Yes I agree about Flash, that's what I said previously, the only value Flash provides is that of an authoring tool. My contention is that it need not output to it's own data format to do what it does as an authoring tool. It bypasses what the internet is and what web browsers were designed to do, render web content. In the case of Flash, your browser is just a vector for Flash and isn't acting as a real cross platform device independent internet browser.
One note. I am a developer of web apps, OSX apps, and iPhone apps and have been creating full fledged large scale enterprise class web apps since 1995 on NeXT's, before Macromedia even released Flash. I saw Flash when it was introduced and have seen it progress (infect) web sites and occasionally actually used well also. That said...
Instead of creating a web app for your client that runs in a web browser they get a Flash application that runs in the Flash player in (a few) web browsers and on desktops as stand alone apps? So, IMO, it's just another implementation of Java, but not nearly as good at most things and better at some others. I can understand how and why you and your client are fooling yourselves into this understanding, not that I personally have a currently available solution, I don't... My point is, why SHOULD Flash be needed? Flash is an end run around html to avoid a bunch of technical difficulties with browser rendering implementations and continually evolving web standards.
For example I can use a text editor to write OS X apps, but I do not. Instead I use a development environment (aka Authoring Tool). It does a bunch of things for me that I would otherwise need to do manually, increasing my productivity.
I'm not talking about a dumb old school WYSIWYG html editor, but a real html authoring tool or development environment. It should take care of the cross browser stuff for you and generate code to the spec.
Let me sum up. We need a multi pronged approach. Web browsers need rendering tests akin to the javascript stuff out there to judge how compliant/complete they are (maybe they already exist, IDK), we need to author code to the html spec instead of a specific browser or browsers and the browsers need to be viewed as broken instead of the web sites that are written to spec but rendered incorrectly in a specific browser, and we need real development environments / authoring tools that generate smart and optimized html/javascript content to the html spec.