Gah - a solution with more questions. – EntropicLqd
Kismet 2[confirm] or K2 is a visual programming feature. K2 is not confirmed by Epic Games and is therefor pure speculation from the community. K2 first popped up in the recent UDK builds starting with the K2 modifiers such as K2Call found in various classes. There are as well many new classes with the K2 prefix that are very suspect to be related to a new upcoming visual programming feature for the UDK.
By looking at the classes it's clear that this is designed for a visual programming feature for UDK, they can be found in UDK-2010-07 and UDK-2010-08 in the Engine folder of Development\Source. Some of these classes are named K2Node_Code, K2Node_ForLoop, K2Node_Func and K2Node_IfElse.
Unreal Engine 4
Indicated by the source code of UE4 it is clear that K2 is the codename of Blueprint.