Some sketches and specifications of the coming Samsung Galaxy Note III (SM-N900) has leaked. I don't know if they are real, but in these specifications we can see that it has a 5.7-inch FHD AMOLED display, and that goes against what I believe. I believe it will have a 5.99-inch display.
Other specs are 13 megapixel camera with a XENON flash and dedicated shutter button, Exynos 5 Octa processor or a 2.3 GHz Snapdragon 800 chipset probably for the US. And the way that is written on these sketches, doesn't look "professional" to me.
Samsung will probably announce the Galaxy Note 3 on the IFA show in Berlin in September 2013. Or maybe just before it or after.