I might as well post here.
The CNN article is wrong. Your signs did change, and it doesn't just affect people born post 2009.
So a bit of history about astrology:
It was ORIGINALLY based off of the sidereal zodiac (the same type that eastern astrology is based on and the one where the sun being in certain constellations when you were born determines things).
Ptolemy, who wrote one of the oldest surviving books on astrology, was trying to define dates to use to define when one sign began and one ended. He chose his reference point to be the vernal equinox (spring) as it marked the beginning of the new year and it lined up fairly closely to when the sun passed into Aries at the time. So he pegged Aries to the beginning of spring and then chose other dates for other signs accordingly.
He did this only as a proxy for the sidereal zodiac. He did not anticipate the need to adjust the dates due to precession. He thought the vernal equinox would always coincide with the sun passing into Aries. This is the flawed assumption on which western astrology and the tropical zodiac are based.
Due to precession, the dates that the sun passes through certain constellations in the zodiac has slowly changed. Nothing special happened in 2009. If the new chart says you are now a gemini, guess where the sun actually was when you were born? Yup, gemini.
The notion that the signs didn't change because it is based on the seasons and not on the sun's path through the ecliptic goes to further astrology's bullshittiness (if they can make shit up, I can invent new words). The seasons are a flawed proxy for sidereal astrology, and thus western astrology departs from the original foundation which is based in sidereal astrology.