My thoughts on a few on that list:
Addictio: 11 posts total. Talk about contribution. Must have been earth shattering.
Nephi: Not posting anywhere it would appear. Oh I remember, got pissy because not enough women would say if they liked to take it in the poo hole. Remember that?
Froggie: Posting mostly at the foyer
Tal Bachman: Not posting on any boards lately, only posted here briefly while he got owned royally by Tarski on a thread
Kevin Graham: He'll be back
Runtu: He'll be back, on Foyer
maklelan: Back
Analytics: Posted recently, posted alot before the election
A Light in the Darkness: Had one major spell of posting, did liek 100-150 posts out of his/her 300ish in one day.
DonBradley: APparently has disappeared, possibly to be the love slave to some alien princess
Loquacious Lurker: only posted briefly as I recall
charity: Apparently has disappeared off the face of the earth, not appearing on any boards
But it appears people go in cycles. Let them. Anyone who is invested enough in the board to be worried when people don't post should probably do as those posters probably have done, and diversify the activities in their lives. I myself have taken that advice by the way...

Whatever appears to be against the Book of Mormon is going to be overturned at some time in the future. So we can be pretty open minded.-charity 3/7/07
MASH quotes
I peeked in the back [of the Bible] Frank, the Devil did it.
I avoid church religiously.
This isn't one of my sermons, I expect you to listen.