Science Magazine, for its 125th anniversary, presented a feature on the Top 125 Questions of Science. I've taken a cursory look at the top 25 on their list, and it looks to be very interesting reading, leading to several tangents and avenues of inquiry.
Half of the top twenty-five questions pertain to life sciences, and much of it covering medical interests. This is the trend of this century, it seems: how to extend and enrich human life. Still prominent, though fewer in number, are questions about the physical nature of the universe.
I guess it will take a while before humanity as a race will start looking outwards to the stars...where we belong.