http://services.runescape.com/m=news/behind-the-scenes---december-2
Direct quote:
Damage Soaking and New Hit Splats
We have recognised an imbalance between the potential damage per minute (DPM) and damage capacity (DC) of higher-level players. The rate of damage that you can deal at high levels is far greater than the rate of damage you can withstand, especially when in a multiplayer environment. NPCs and boss monsters can deal with this issue because their life points can reach far beyond 990, but players' life points cannot. Dealing with this imbalance will be done in several ways, with the first of those ways being introduced this month in the form of damage soaking.
In what will be a huge addition to the Defence skill and defensive equipment, we're aiming to add damage soaking stats (currently only applied to the chaotic, eagle-eye and farseer kiteshields) to the majority of head, body, leg and shield slot equipment. Damage soaking will help reduce all incoming damage values over 200 life points, with higher grades of equipment offering a greater percentage of 'soak', and with members' equipment offering the greatest percentage of all.
We're also looking forward to releasing a brand new set of hit splats to give you better information about any combat you're in. We’ve had some great conversations in the forums after the dev blog about hit splats a few months ago and have changed our approach thanks to your excellent feedback.
Once launched, you’ll be able to:
Identify your character's damage in multiplayer situations, so you'll know which splats are yours when fighting boss monsters with your clan or group.
See visually how much damage your armour is soaking.
Identify the type of damage being dealt to you, allowing you to adjust armour and prayers more accurately.
Identify reflected damage.
Use the 'max hit splat' to easily spot when you’re dealing huge swathes of damage.