Nerf/Disable Leeching at release

So I made a comment about leech in the open beta promotion thread and since there were some replies, I thought it'd be better to make a thread for it.

Now people have very different opinions on if leech is good or not, so I'm not going to repeat all the arguments over again. Instead I'll make a suggestion on how to possibly improve on this:

Now normally whenever a mob is killed the source distributes the exp to everyone in the party. What I want to suggest is: make it so that the exp is only distributed to players in the party who have attacked in the last minute or so. The attacked mob would have to belong to the normal spawn of the map of course.

This would mean that party training is still possible, but people can't afk for an hour and get leeched.