Apple spokesperson:

We're discontinuing the Apple Thunderbolt Display. It will be available through Apple.com, Apple's retail stores and Apple Authorized Resellers while supplies last. There are a number of great third-party options available for Mac users.

It wasn't too hard to see this coming. Simply put, the Thunderbolt Display's technology is long in the tooth. These days, the $999 official price can get you a good ultra-wide Quad HD or 4K monitor, occasionally with Thunderbolt built-in (such as LG's 34UM95-P). It's certainly not the most tempting option in Apple's roster when you can buy a similarly-sized iMac with a 5K display. Also, the screen's use of first-generation Thunderbolt left it behind the times when Thunderbolt 3 is starting to show up in some PCs.

The big question is what happens next. Apple isn't saying yet, but there are a couple of options. It could get out of the monitor game entirely, of course, and leave the market to companies with more aggressive pricing. Alternately, this could be preparation for a replacement, which might happen when Thunderbolt 3-equipped Macs (necessary for 5K external displays) hit the scene. One thing's for sure: once the current inventory disappears, Apple won't make everything you need to outfit a Mac mini or Mac Pro. At least for now, you'll have to turn elsewhere to get that missing piece of the puzzle.