Since you asked, Aya, here's how we handle it at 2P these days.
We are wide open for communication, but players have to care enough to do some work. We offer gamewide OOC plot chats every few months, and I am always so thrilled with the results - we go through current and upcoming wizard-run plots and do our best to hook characters into them. This time around we offered individual plot chats beforehand as well and they have sparked several player-run storylines.
And for the original question: Our requirement for XP for impression means we don't often get ledge-sitter candidates. We also have a policy where if you can't prove you've RPed for a few months, we'll unapprove the char -- in practice we've only used it once.
Personally, I have no patience for ledge-sitters. If they ask for help with getting back into RP, great! But I'm not going to prod people into RPing if they don't actively want to. I ain't got time for that.