Whats to keep samsung from copying all the tech for the new SOC and using it in oh.say. a new galaxy tab ?
Nothing, and they even have the right to do that if they wanted. Apple's A5 uses two ARM Cortex 9 cores, just like TI OMAP 4 and NVidia Tegra 2 for example. The GPU isn't designed by Apple either, it's done by Imagination Technologies. Any chip maker could use the same PowerVR SGX 543MP2 if they wanted, but most have chosen a lower-end GPU (that's a two-die GPU so it's quite expensive, and there are plenty of other bottlenecks too).