Flash being a resource hog is down to bad coding of the flash applications rather than the runtime itself (the runtime isn't a masterpiece of efficiency or anything but it isnt intrinsically a resource hog).<p>All the crappy programmers making punch the monkey flash ads will just make punch the monkey html ads and you wont realise what it is consuming your battery.<p>Also, "Thoughts on Flash" is full of easily verifiable lies.
What I don't understand is why Adobe hasn't made HTML5 a supported compilation target for the existing Flash tools. Yes, tons of work. But a great way to stay relevant in the web app development space.
I do some Flex (Which is build on Flash) contracting, the money is crazy and there are some Flex/Flash applications out there that I don't see getting replaced by JS anytime soon.