I've done something similar with my prototype explorer, though it's using websockets instead of polling the server every x seconds, which is imo cool. The browser support still sucks, however (and my html&js skills, too, for that matter - guess i'll just focus on finishing the damn electrum client finally in my next coding session).

it sure looks nice, but adapting it for yac seems kinda challenging given most things are hardcoded in multiple places. also, i don't like the prospect of running Yet Another leveldb alongside the electrum's with essentially the same data. (and neither do i like node.js )