The 21:9 monitor is a successor to the 34UC79G from LG, which also ran at 144Hz, but supported FreeSync instead of G-Sync. The 34UC89G features a widened color gamut, unique display modes including black stabilizer and dynamic action sync, and the refresh rate can be overclocked to 166Hz.
The 34UC89G comes in at $999, and will be available at retailers including Amazon, Newegg, and B&H later today.