Earlier quoted context omitted.
Since Adobe's fat margins were from authoring tools, presumably that opportunity still exists. AFAIK none of the existing HTML5 authoring tools are close to Flash in power.
When you own both the authoring tools and the runtime, the world is your oyster. Sure, HTML5 authoring tools suck today, and it will be a huge boon if Adobe leads the way to the promised land. But the barriers to entry for others to then go the same way is so much lower than in Adobe's previous environment. Well, it will be very interesting ride over the next few years!
Can you not just target Flash Player? Seems like the barrier to entry is going to be the same as Adobe's in either case, except that with Flash, Adobe must also maintain Flash Player.