Personally I thought Slayer was useless when it came out and I still don't really like it, though I am trying to train it. We already had several combat skills. All Slayer did was mandate what monsters you had to kill. I can see Jagex's point in using it to clear out other popular combat areas of rs (shadow warriors used to be packed) but I don't like new skills that seem like continuations of or additions to old ones. I don't know what new skill I would like. Maybe something that you can make useful things with. Maybe something along the lines of inscription, like in WoW.