I might agree that for very small icons (eg: targeting a ~VGA or 800x600 to maybe 1024x76 phone screen) hand painted bitmap graphics might be best... but should

I might agree that for very small icons (eg: targeting a ~VGA or 800x600 to maybe 1024x76 phone screen) hand painted bitmap graphics might be best... but shouldn't it be enough to ship 16x16 (or whatever) icons along with vector graphics for high-resolution screens? And if it's too slow to live-render the graphics, how about rendering custom icon sets (etc) on install - using the gpu, and then cache on the device?