Flash has a fantastic editor though. To be able to make stunning vector gaphics, animations and to code easily with a ton of frameworks... well it just lets you have your cake and eat it too. HTML5 is great though it lacks a friendly editor which means you have to make your resources in other programs and code it into Javascript. Thankfully the big plus to HTML5 is compatibility across platforms without a need for a plugin.
Flash has been a great tool for me in the past but I feel its time has passed unless it moves into a different direction. The emergence of jquery and the likes has made Flash less important and with HTML5 now here I feel Flash will be a thing of the past.
I cant really say because I don't know Flash much but I have to go with HTML5 right now because that will be more important to me.
