Ziad S :
Is it worth?will there be a noticeable performance in gaming?or i am better off getting a second gpu
Actually, that really depends on the motherboard that you have. What's the chipset? If it's Zxx then I would go for the 2nd GPU, otherwise "tough' it out waiting for the 14/16nm node of your choice. (Pascal for team green/Arctic Islands for red) Check the reviews and get what's best (that you can afford)
The CPU upgrade won't be a significant benefit.
Of course, if you do go the 6700K on a Z170 motherboard (why would you pick anything else for that CPU) then you would be able to go SLI in the future.
Actually since MB, CPU, 8GB and CPU cooler (which you may be able to re-use if you aren't using the stock 4670 cooler) shouldn't be much more than a 980ti anyway ... A major swap now would align much better with whatever comes in the future.
OK, now I'm leaning more towards the swap of the major components. (Final answer)