I think that when people PM you while you LS, it should show you that you have received PM(S) as you are slashing. This can be good for someone who is waiting to here from another user, and loses track of time. Also, if they have something urgent to talk about, then they wont play "PM Tag". PM tag being User-One sends a response or PM to User-Two (while User-Two is away and/or idle from the site on LS). User-Two, needing to talk to User-One urgently, needs a way to know when he is receiving PMS while he slashes, in order to settle the matter, instead of always responding too late. (not giving them the chance to be able to exchange fluid PMS)
An Example could be as simple as making the new addition of the "Drop Down Box" inclusive in your LS window..
LMK what you guys think