It's here!

https://www.runescape.com/nxtupdate

Changelog:

• Made a change to reduce potential dead inputs, especially at lower framerates.
• Fixed misaligned interface borders in dungeoneering floor completion interface.
• Fixed an issue causing players to occasionally stall briefly after completing a lodestone teleport.
• Fixed an issue preventing the game window from correctly resizing when double clicking the title bar on Mac.
• Fixed special characters sometimes causing messages to overlap in chat.
• Fixed quest markers sometimes disappearing from map.
• Fixed an issue with particles slowing down Mac clients, an example of this is P5 on Telos.
• Improved loading times when loading into an animation heavy areas.
• Fixed water rendering on Anachronia.

Restart your clients (if you already have 'em open) to get it!