This (along with the Filters spec, with has a lot of overlap) are quite welcome for me. - Real drop shadows! It turns out that many modern UIs have objects wit

This (along with the Filters spec, with has a lot of overlap) are quite welcome for me. - Real drop shadows! It turns out that many modern UIs have objects with irregular shapes. box-shadow only does...boxes. Not terribly useful. - Real glow! See above. Lots of times you just want to be able to say "make that thing glow". Oh, it's not a rectangle? You're screwed. Time to make a sprite. Which you will have to edit and upload every time you tweak the glow. Ugh. - Blurring effects! You can do all sorts of neat things with this. - Color manipulation! Say you want to darken an element when a user clicks on it? Can't do that right now. - Distortion filters! Very useful for making games. You can create all sorts of crazy scene-warping explosions. Yes, browser inconsistencies suck. But other than that...you know, HTML/CSS/Javascript isn't that bad. Flex/Flash/WPF/Android/iOS are really not that much better. They're all good at certain things, but in the general realm of "creating interfaces" they all have issues.