Daily, unless it is some automated thing that goes based on simple posting/viewing activity, would be too much work, wethinks.

On a slightly less frequent frequency could work, though. Either as part of the newsletter, or as something independent. In fact, having people working solely on that aspect might make the newsletter even better, wethinks. per today (based on view of the first guildrisen newsletter), that section seemed a little skimpy.

Top 10 notable RP's of the year would seriously favor the few RPs that manage to survive that long. Maybe have it instead be one of these two?
Monthly 10 great RPs
Bimonthly hall of fame

Having such a system to spread info about the greater RPs might also help more RPs reach longer lifetimes. It could also filter a little on the various interests. should not focus solely on one or two types of RPs.