interesting....
Getting it implemented isn't hard, but it seems there are still some restrictions after playing with it a bit...
It works for the div container on the main site for instance but not for the top menu link hover which is inside a table.
Also the archive with several divs inside each other isn't behaving consistently.
I left it for the main page so it shows at least the corners there but anything else is too much work IMO.
I did say after all I wouldn't go to any lenghts to support non -standard browsers anymore