Hmmm, I think anyone can learn how to produce, if just tought by the right people. I however dont think that you can teach anyone to make a killer track writer. Why you ask yourself? Well, techniques are easy to learn, its like math or anything else, you just need a brain to memorize the stuff (of course this is my opinion only, i know others totally disagree with me here! ).
I mean, there are laws in producing, and people follow these laws very acurately, however, its the ones that go beyond those laws, and experiment with the sound, that often make that so called killargh!
Another factor is Simplicity, the one that makes something very complicated/melodic/driving with just a few simple sounds. (See Plastikman).
So yeah, talent and also the ability to learn are factors. The BIG question though is, how do you find out that you are talented?! How do you bring out the talent in a person... we can never know for sure. I mean, Radi migth do a track today that to us sounds like crap, but in 2 years maybe that will be the new style of PSY (Im not joking here!). Does that then make him talented?! WHO decides who is talented?
Nemo