Can it be used to render pages? That's still something I desire.
Now if Google would use such a system for all their crawling, instead of forcing us ajax-app authors to implement their hackish hash-bang "solution." I'm guessing they would if they could, but the cpu cycles are just too expensive still.
(I originally wrote "delicious/pinboard clone" instead of "bookmarking/archiving site" but I realized we've had it since before del.icio.us launched.)