Perhaps I missed it in the specs or in one of the (many) comments above, but has anyone suggested a property for clipping borders or something to define how far a border spans down each particular side of an object? Something like this:
border: solid 1px #000;
border-left-clip: top 50%;
border-right-clip: center 50px;
border-top-clip: left 50px;
border-bottom-clip: center 50%;
Also, more alpha/transparency controls on backgrounds, borders, etc. would be great as well as multiple background images. I love the idea of support for SVG in background images too.
These specifications look great, thanks!! Now all we have to do is wait 20 years for IE to start supporting it!