We've always said Flash is going to die, but it will be a slow painful death. It's got such a gigantic web footprint that wont fade quickly, and also there's a TON of professionals out there whos livelihoods depend on it. They will squeeze it (understandably) for all it's worth. It's hard to say when, but if we try and look 10 years into the future which in terms of technology is a vast amount of time I really can't see any serious new Flash development going on.