Seriously, people? No single tool of introspection is going to match one for one with another. the MBTI detects (relatively) four different (and rather limited) dynamics of typical thought processing. E-I reveals where your default source of information lies...from without or within. Do you by default collect information through your five physical senses (S) or your ~6th sense (N)? Do you evaluate the information according to your emotions (F) or according to thought (T)? How do you apply the information, by making thoughts more concrete (J) or by allowing perceptions to grow (P)?
Astrology on the other hand (google Suzanne White) attempts to explain situational dynamics of individuals through their seasons of birth. It isn't entirely without reason that such systems have been perpetuating for so long: gravitation, light, temperature, and a lot of other things subtly influence the way individuals and the general population behave. Depending on when and where someone was brought into the world, the most likely disposition they would have can be predetermined...and if they fail to mature, they end up working just as the records say.
Reasons as to why they apply to some people: These people fail to acknowledge their personal tendencies, lack knowledge of themselves, and essentially do what the predictions say. There are others who become aware of the forces at work within their own personalities, and can thus manipulate themselves. In fact, some people are aware of this even without zodiac readings and laugh at the one-true story of their life, while they progress to adopting other traits.
So, yes, there are some correlations. No, they are not entirely 1 for 1. Perhaps you may meet your doppelganger, but you will never find a "twin" of any sorts when you look deep enough, or use an array of evaluations.
And the poll simply reveals that the top three signs of the western astrology to contain INTPs are Gemini, Cancer, and Virgo....at least on this forum. Change the sampling, and the results may change.
...but what the hell, this just told me something I like to hear anyways. My fiance is Virgo, and I am Gemini two days away from Cancer.