Well, PNGs are nice and all, and so is animation. So, animated PNG support would be nice!
See bug 17022 for a discussion of how this is platform specific.
For Safari, APNG support would require changes in ImageIO that are tracked as <rdar://problem/5618737>.
Big thanks to whoever implemented APNG in Safari!
Apple should make an official announcement about it.
Nitpicking now... frame blending is a little bit buggy:
URLs for testing: