Consistently better quality ? I'm sure that can be hotly contested by many on here.
Typically when Apple introduces a new display, it's better than the competition at the time. You can certainly make an argument that the display portion of the Thunderbolt Display has been surpassed by the competition after three years, though I tend to think that a greater portion of Thunderbolt Displays will be still in good condition (no burn-in, ghosting, etc) than the competing devices will after 5-10 years (Monitors tend to outlast the computers they are initially paired with by a long time).
You do know that the Thunderbolt display is just an LG panel with a nice case around it ?
The Thunderbolt Display is an LG panel wrapped in a nice case with additional I/O (USB, FireWire, Camera, audio, ethernet) all connected through a single connection to the Mac. If someone only cares about the display itself, by all means, do not spend the extra money for the Thunderbolt Display. But if that additional I/O and the ability to basically setup a docking station for a MacBook is something that is wanted, then it may be worth the extra cost.
If you look at the Thunderbolt Display as Apple's docking solution for the MacBook Air and Pro, it becomes a lot more interesting. It also happens to be useful for the Mac Pro, Mac mini and iMac, but given that most people don't move those machines around like they do with their laptops, it's not as helpful for those machines. When I was using an iMac and Mini as my main machines, I wasn't about to spend money on the Thunderbolt Display. But with the MacBook Pro, it was a no brainer for me.
Don't get me wrong, I'm not rooting for them to drop displays. In fact, I hope you're right! I just think any line that hasn't been refreshed in over 3 years is being put out to pasture.
Many folks were hoping for a new iPod classic until recently or a better Mac Mini.
I would say the current model Dell UltraSharp & NEC Multisync are better monitors at similar prices to Apple and the Samsung 28" UHD Monitor at less than $600 is a crazy price. I have no bone in those brands, personally I use a 27" 1080p IPS monitor by HP that I got on sale for $199 with my Mac Mini.
It's certainly possible. We have no insights into what Apple is doing, but I personally have a hard time believing that Apple would invest in making a custom TCON chip for the iMac 5k and not want to bring that to the Thunderbolt Display at some point as well. From a R&D perspective, the Thunderbolt Display is almost a freebie. Take the iMac, rip out most of the guts and stick a Thunderbolt interface on it. And then sell it unchanged for the next 5 years or so.