Adobe is just doing what is best for their shareholders. Can't blame them really.
Before HTML5, they had more of a monopoly than Microsoft had on the desktops when they were sued. Now Flash has competition with all the browsers. It's a mandate that they all have to do what they've just left to Adobe to handle with Flash.
It'll be an interesting show. I for one am very excited about this because it eliminates a lot of uncertainty about the web as a platform moving forward.