Kaveri benefits from GDDR 5 and considering its not a socket change or SoC there is not enough space for an embed on the die itself so FM2+ will likely have the GDDR5 embeded on the motherboard itself with extra controller in the NB to allocate it exclusively to the iGPU, as for the rest it will be like Z87 is from Z77 thunderbolt, faster SATA, better VRM's, Faster RAM speed support and of course allowes mobo manufacturers to remarket and redesign.
Can we drop the "Kaveri will have GDDR5 memory" rumor?
1) its unsubstantiated
2) it's contrary to AMD's own roadmap for how they are planning to update their APUs.
AMD is planning, with Kaveri to do what they did with Jaguar, and eliminate the "graphic ram/system ram" wall that currently exists in APUs/iGPUs everywhere. This is a key redesign which allows the cpu/gpu to work on a task simultaneously inside the same ram.
Adding gddr5 ram to the Kaveri motherboard would invalidate this whole structural redesign. It won't happen. A llano/trinity/richland APU would benefit from an inbedded chunk of gddr5 ram... Kaveri would not.