Yeah, I've been hearing about this new change on the news.  So, two questions here:

a) do you use the sign you were born under?  or the sign of your birthday this year? 

b) is the universe expanding or what?  how do you go from 12 Zodiac signs to 13? 

P.S.  I don't read horoscopes anyway.  So it's a mute point for me.