Even though I'm the one who originally suggested weighting top-post karma more than comment karma, I've felt that 10 karma per vote for a top-level is a bit too much. Five karma would seem more appropriate, weighting top-level posts more but also giving a more realistic option to climb in ratings via comment karma alone.

I wonder if a "top 100 contributors" page, with both all-time and 30 day options, would be a good or bad idea. It might more effectively encourage participation, but also make people more addicted and possibly cause undesirable status dynamics.