One person starts a thread named MSN Adsense? at WebmasterWorld and before you know it, you have ten replies.
I have no heard of any MSN AdSense program. Of course we have the new MSN adCenter Pilot Program but any word of a contextual ad program like AdSense or YPN? Not that I heard of.
I am sure they are thinking about working on it or actually working on a contextual advertising program. But right now, nothing that I know of.
Update: JenSense has some info on this from a while back, MSN jumps in with talk about their new contextual ad program.