"And Jacob called unto his sons and said, 'Gather yourselves together, and I will tell you that which will befall you in the End of Days. Assemble yourselves, and hear, O sons of Jacob, and hearken to Israel your father.'"
Notice how Jacob emphasizes two things: there is a need for everyone to gather together, and they should listen closely to what he has to say. All of this precedes the actual giving of the blessings. In other words, Jacob was hinting to the fact that the prerequisite for receiving the blessings was unity. First they had to come together as a family, and only then could he give each individual a blessing tailored to their place among the Jewish people. What followed were descriptions of how each of the Twelve Tribes of Israel assumed a unique role. Some engaged in commerce or working the fields, others in religious study, and yet others in military or temple service - and all were essential to the survival of the nation.
We must do our best to overcome the inclination to force others into living their lives exactly as we'd like them to. Whether we think that all Jews should pursue postgraduate study and enter a medical or law career, or pursue religious study and enter the rabbinate, or any other path - one way of life does not fit all, and Jacob was alluding to this. In addition, we can derive from his words that while each one of us serves as a unique individual among the Jewish people, we must conduct ourselves as a larger family. We should never disregard others just because of their different approaches to life. In fact, it is precisely because of our differences that this formula works.
This brings to mind a related lesson. The chelbonah (galbanum) was a spice with a foul odor that was included in the Temple's incense service. In the absence of this spice, the entire mixture was rendered invalid. Although one would think that only pleasant-smelling spices would create the best mixture, when the chelbonah was mixed together with all the other fragrances, it produced a beautiful aroma. Our Sages note that this is to teach us that even Jews who do not engage in righteous behavior are an integral part of the Jewish people. Every single Jew - no matter how great or how lacking in deeds - is important in the eyes of God.
From an historic perspective, it appears as though we are living in the End of Days, a time in which the world will eventually change for the better. The only way to get to the desired destination of a better world is by heeding Jacob's call. The message behind his blessings is as relevant today as it ever was. We are each individually unique by design and are asked to use our God-given talents for good. But when all is said and done, it must go along with good treatment of fellow Jews. Whether we like it or not, we're one family charged with bringing God-based goodness to the world. In a veiled way, Jacob was letting us know how to succeed in our divine mission.