Microlight and SLMG Instructor Ratings will be available for NPPL holders with the relevant NPPL Aircraft Ratings in order to continue with current SLMG and Microlight instructional practices. I.e. "Same thing, different name".
There are NO currently agreed proposals to introduce a SEP instructor rating for NPPL holders; so for the foreseeable future, to instruct for the NPPL once you have achieved the required total of flying hours your minimum requirements (for unremunerated SEP Flight Instruction) would be a JAR-FCL PPL(A), a pass in the JAR-FCL CPL(A) theoretical examinations and to complete a JAR-FCL FI(R) course.