Shhh! My common sense is tingling.
While I don't completely buy the tables over css layouts part (though depending on the layout it is possible...) the rest of it makes sense.
Large images in particular can cause real drain because they have to be decoded; that 260k jpeg might look cool, but decoded it takes a megabyte or more of RAM on devices that typically have less than 64 megs free by the time the OS and applications are loaded. That means dipping into the fixed storage to swap, consuming even more power. (and shortening the life of said storage since, well... it is flash RAM!) .. and that's without talking the overhead of running the decoder algorythm... especially since jpeg is lightweight compared to what PNG uses. (zLib) -- to put that in perspective that's like saying a rhino is lightweight compared to an elephant.
There was an article by one of the android devs a year or two ago (my google-fu is failing me) where it was said smartphone battery life could be doubled by killing all the cutesy transition animations. Stood out in my mind because I'm not a big fan of stupid animated transitions in the first place. I click on something or tell the computer to do something I want it done NOW, not sit there waiting for some stupid animated dog to ask me if it can help me.
... and to be honest, fade, genie, and other transitions are as annoying to me as Clippy or Rover. Rank right up there with the idiocy of rotating image banners sucking down space for nothing useful -- well, apart from hiding the lack of real content on the page.
Because the real problem with flash wasn't with flash -- which is great for games or video delivery. The problem was people using it on websites for garbage that shouldn't even BE on websites. The problem isn't the technology, it's how it's being used, overused, abused, mishandled, and thrown at EVERYTHING 'just because we can'.
Though you are right -- they should be wisely used; I say use with an eye-dropper everywhere, and drop certain effects completely for mobile. Just slapping endless effects on a page "because you can" is the real problem, regardless of technology.