Could it compete with an AMD GPU?
Of course not. It's not a GPU.
But it will be very useful for the socalled "cpu coins" like litecoins and others.
And, more important, for scientific things that run bad on GPU cause of low cache.
Correct. This is a pretty specialized cpu and is not going to be good for most tasks. It has nothing like the number of cores in a GPU, but they are easier to program. It won't make your desktop faster with a 1ghz clock rate, and it won't make your graphics faster then a standard GPU. But for science and complex formulas that can be broken into threads, it is going to be killer.
And if for some reason CPU coins are still around, it will be choice of CPU coin miners and do in standard cpu's for that job.