I like the idea and this has been an issue I've felt while following most HN Twitter feeds but the implementation is a little.. shiny. If you made it a bit more basic (fill the window for starters, no need for the giant margins) and ditched the transitions, it'd fit in better with the geek aesthetic.

Also, consider branching out to the firehose sometime. I come to HN anyway so I don't really need such a thing for stuff that's already on the front page, but having everything in /new with something like this means I'm more likely to vote it up :-) Anything that encourages people to monitor /new is a big win.