Re: the timebox. I noticed that the 'strongness' of it makes the whole page jump visually when you update them en masse at each poll. I don't know what to think about the time-ago being updated live, too, while we're on it. Maybe some kind of subtle way to change them will help?
Re: mix of stories. I'm currently staying away from Techmeme (had to disable my no iPhone/Android news user script to actually compare the headlines), so my input there is of marginal use. I'll say that the headlines didn't put me off - there was good diversity of content instead of half the page being filled with hoopla about cellphones. I learned about Real Time Farms[1] from a lifehacker story via the Kitchn blog, so that's something!
1: http://lifehacker.com/5589590/real-time-farms-is-a-user+supp...