I've had similar thoughts, though my time limit was 5 or 10 years, rather than months.
My other thought was to tie it to current events, so if Iraq was in the news then dig out something from the archive that takes a long view, you'd probably learn more than you would from a list of who died yesterday.
Part of the idea was that we have "event bias". Lots of meaningful things happen in the world without any significant event. Look at gap minder or green revolution.
"Great minds discuss ideas; average minds discuss events; small minds discuss people." -Eleanor Roosevelt
Personally I don't like the idea of ranking people. There is nothing wrong discussing people or events. But I'm natural idea person and most websites have very poor signal to noise ratio in that respect.
My other thought was to tie it to current events, so if Iraq was in the news then dig out something from the archive that takes a long view, you'd probably learn more than you would from a list of who died yesterday.