If you're based in the US and ordered one of LG's new UltraFine 5K Displays, then your monitor will be shipped in the next few days - as Apple is now sending out pre-shipping notifications.
MacRumors reader Jesse, placed an order for one an LG UItraFine 5K Display when the order window was open in late November, and has recently received a notification that his 5K display will be delivered on December 28/29. Apple began taking orders for the LG UltraFine 5K Display on November 28 with 6-8 week shipping estimates, but the supplies were diminished quickly, with no more available to order.
The 5K monitor went on sale again today, with a shipping estimate of 3-5 business days, quickly slipping out to 2-4 weeks. Those who ordered quickly this morning should hopefully receive their new LG UltraFine 5K display later this month.
Apple is still providing its discounted pricing on the LG UltraFine 5K display, costing $974 - down from its retail pricing of $1299.