The posts on the subject abound all over the internet:
HTML 5 versus Flash / Flex
Adobe was heard saying:
It might be a decade before HTML 5 sees standardization across the number of browsers that are going to be out there (…)
Right.. I think it will take 2 years. I think in 2 years, you better get really good with the Google Web Toolkit if you want to be on the cutting edge. Otherwise, you can wait 4-5 years. And who will save our jobs: Microsoft. By being the shittiest browser out there, Internet Explorer will help keep the value of actionscript knowledge high for atleast another 2 years.
That is my take. What is yours?