Running NoScript and only enabling javascript and flash when needed likely has a similar effect. The advantage, of course is that with Flash installed but disabled, you can enable/disable it as desired and as battery permits.
You know, what you say brings to mind an interesting point. Right now most people ~98% I think, have javascript enabled all the time. Its a smaller minority of us that use NoScript.
There are no mechanisms that I know of in popular browsers to disable certain html5 features like canvas, video, or audio elements.
So while its possible right now to disable Flash by not installing it or using certain browser extensions, if an ad provider loads an ad that uses the video or audio element you really have no way to disable them. Disabling javascript should prevent canvas-based ads from running, but what's to stop video and audio playing if your browser supports autoplay?
No doubt extensions will be created (or more likely, support will be added to the existing Flash- and/or ad-blocking extensions) if this becomes a significant problem.
