The new parts showed up on the compatibility list of socket FM2+ motherboards by BIOSTAR and it is not clear when they will be in the shops.
The architecture mentioned is "Kaveri," but the silicon could be "Godavari" which is a Kaveri refresh.
The top of the range will be the A10-7890K, which has CPU clock speeds of 4.10 GHz out of the box. We do not know what the TurboCore frequency will be, but the current A10-7870K offers 3.90 GHz with 4.10 GHz TurboCore. The A8-7690K has a CPU clocks of 3.70 GHz. We are not sure what the iGPU clock speeds of the two chips.
The Athlon X4 880K is the most interesting. It has 4.00 GHz CPU clocks. The Athlon X4 FM2+ series lack integrated graphics that means that they are good for those who will buy discrete GPUs, on the FM2+ platform.
All three chips offer unlocked base-clock multipliers, enabling CPU overclocking.