They revamped monster play with the new expansion but I haven't looked into the details. Here's a dev diary outlining the changes. You don't lose everything if you go from VIP to premium, so that's something, at least. From the link HalibutBarn posted up-thread: "All characters logged in while VIP keep the unlocks for bags, traits, gold cap and swift travel". Turbine lets you pay to permanently unlock most stuff so if you don't want to subscribe there are only a few things you'll miss out on completely (like rest XP). I wonder what the cost of getting all the 'good' unlocks is vs. something like GW2's $60 box cost that covers everything until an expansion hits?