There is already a thread about this here:
http://www.wowinterface.com/forums/s...ad.php?t=49307
This change does not affect your ability to hide/show nameplates based on the player's combat state. As with all other "not allowed in combat" actions, you can still set any or all of these CVars in response to the PLAYER_REGEN_DISABLED (entering combat) and PLAYER_REGEN_ENABLED (leaving combat) events. This is how these events have always worked since the 2.0 patch that added combat restrictions and other UI security measures in the first place. If you've been using some other events to detect the beginning and end of combat for the purpose of altering the UI based on combat, you've been doing it wrong.
It does, however, prevent addons from showing or hiding nameplates
while in combat, and you should expect errors to occur if you try to set these newly protected CVars while in combat.