I know talk of a tiered system has come up with some frequency over the last year and a bit, and I suspect they'll eventually implement some version of it. Depending on at what level they actually start the first tier, we may or may not have enough to qualify for any additional perks, and that's ok with me.
As long as they add additional perks for higher point owners, and don't take away too many things that lower point owners have gotten accustomed to, I don't think they'll have too much mutiny from current owners. It could be an effective marketing device to get someone to buy just a few more points to access the next tier. I confess that, depending on the perks, it might well work for us.
I do think they'd have to be very careful to limit perks to owners (and guests traveling with them) staying on their own points. They could all too easily end up giving the best perks to those who rent from high point owners, which is the only aspect of this that bothers me. I don't have an issue with someone who has bought a lot of points, and given Disney a lot of their money, getting some extra perks.
Honestly, you can already buy a better experience when you go to WDW. If you pay deluxe prices and stay at club level, you're going to have more perks (lounge with snacks, concierge staff who helps you get the ADRs you want, easier check-in) than someone who doesn't pay for club level, or doesn't stay at a deluxe resort. And people who stay on Disney property get perks that people who don't get. On the hotel side, the more money you give to Disney, the better perks you get. Why wouldn't they eventually find a way to do something similar on the DVC side?
They want people to buy more points directly from Disney. Anything that encourages people to spend more money to get something that doesn't cost them too much money is going to be seriously considered, and probably implemented.