Developers are very familiar with Flash technology. It has both power and flexibility. Right now Flash owns the online marketing arena. Banners are pretty much written with Flash.
HTML 5 is new. It is based on an open standard. If you are doing mobile apps, HTML 5 might be for you. You might want to learn it if you are a developer. I hear that HTML 5 development opportunities are growing fast.
Companies do not have to choose Flash or HTML 5. You can code up your apps in both, and support multiple implementations of your app. You want to reach as many people as possible. Use the right tools and language for the job, even if you need to support multiple platforms.
Salary Comparison Failure - Read a post that stated top bug bounty hunters make 3X the salary of average developers. Umm what? Who cares what those top people make? You got to compar...