Run of the mill 996s, 997s and 991s will never get restored (and that includes the S versions because, let's face it, they're not that far removed from the standard versions anyway). Want a perfect example of what I mean?
I have an abandoned 997 at my shop for going on 3 or 4 years now (I can't even remember anymore). The customer had bought the car new - with cash - and took it to a Jiffy Lube-style catch-all mechanic at the recommended service intervals (so she claims) but the car still shat itself at 100,000mi (IMS bearing failed). She brought it here, we told her it needed a motor, and we never heard from her for 3 years. It was only after I put a mechanic's lein on the car that she got off her butt to do something. We had a few offers on the car but having PAID CASH for the car she was unwilling to sell it, regardless of what she was being offered. She paid the storage on the lein and then disappeared for another year!! So I leined it again and this time she got the hint; she brought me a bunch of money to buy her a rebuilt motor - with upgraded IMS bearing - and, as a courtesy because I want the job done and gone, I gave her a really good deal on the install. That was 6 or 7 months ago. We got the car running and driving a week after she brought seed money, but since it hasn't been registered since 2008 or 2009 I refused to drive it on the street. I emailed her numerous times to inform her that she needs to get the registration handled so I can test drive her car for her and finish the job ... nothing. Zero. No response for months and months. So the car is once again back outside rotting. The engine has a one year warranty and I can almost guarantee that it will expire before I hear from her again. How I met this lady was she drove the car in because the brakes were making noise ... they were making noise because the steel backing on the pads were hitting the freakin' rotors!!!!! And she was almost through the steel, too!!! How does that even happen? The damn car has a brake sensor with big, frickin' warning light that says you need to change the pads!! And this wasn't just the front ... it was ALL 4 CORNERS!!
If that doesn't illustrate my initial point about "owners who don't know, don't care or both" then I don't know what does. The part that I find to be the most odd is that this is something that she owns and paid cash for. It's not a lease situation so she can't even give it back ... it baffles me.
HOWEVER, I believe that the GT versions of the late-model cars will ALWAYS be collectible. Once they've passed through the hands of the people who buy them as accessories - people who buy them because of how they feel when they see other people's reactions to their car - the cars will find their way into the hands of true enthusiasts who will keep them in repair and/or restore them to their former glory because they love the car itself.
Personally, I'm looking forward to when the 996 GT3s drop below $50K for more than 5 seconds. That's when I'm a buyer. It's my opinion that the 996 GT3 will be viewed in 20 years as the most honest extension of the early 911 and will be the most sought after late-model, standard-production car with a Porsche badge. Minimal electronics, available without a sunroof - the 996/997 sunroof design is a POS anyway - straightforward engineering, tons of aftermarket and continuing factory support for parts and pieces (start stockpiling, boys), and comfortable to drive for extended periods of time...to me, that's a perfect car. I'll take mine in plain white with silver wheels and steel brakes.