No, they don't concern me in the least. We didn't buy in to DVC for the "perks". We bought to save money on our resort costs for the next 40 years. Since we also buy APs every year, we would still have access to the TiW, and even with the price increase that would happen if we lose the AP perk, it would still be worth it to us. As far as discounts go, well, again, we buy APs every year, so would still receive those discounts as well, and the TiW saves us more than the DVC discount at restaurants anyway. I cannot even remember the last time we used the DVC card for any discount other than our APs.
The other perks of special member nights at MK and such, well, we aren't traveling there at that time anyway so can't go to those. Would it be nice? Sure, but it's not a deal breaker by any means. Those are really geared more towards the local DVC crowd than the multiple trips per year crowd like us. And since they are part of the 25th anniversary celebration, we doubt that they will continue in the future.
Might it affect resale values? Maybe. Only time will tell, but again I couldn't care less. We will never sell our points, and our kids all love Disney and will continue to use them after we are gone. If you read some of the posters on these forums, they would have you believe that WDW is nothing but a cesspool of old stuff that has no value to them anymore. Well, that's their opinion, and they are certainly entitled to it, but it isn't ours. We go multiple times per year, have made over 20 trips in the last decade, and we still find new things to see and try every single trip. The value is still there for us.
And while we are not ignoring the changes, there is absolutely nothing that anyone on these forums can do to change Disney's mind on what they are going to do with our membership.