divisive_cotton — 2010-02-07T11:07:19-05:00 — #1
I've been trying to think how this would come in handy in a style sheet
ryanreese — 2010-02-07T11:12:13-05:00 — #2
It's useful for XML but in HTML it would probably not have a use
cooper_semantics — 2010-02-07T11:56:54-05:00 — #3
:root has a higher specificity weight than html does.
Also as Ryan stated, it's useful in an xml context.