From one perspective, what does it matter your state of mind when you die? If you have debts, hates, confusion, whatever.. all done with at death.
From another perspective, I have found that being faced with one's immanent mortality, is often the greatest 'blessing' in a person's life, inspiring such words of wisdom as to 'live each moment as if it were your last'. It allows you to reorganize your priorities; spending some time and attention on with your loved ones instead of your SUV... This knowledge can allow people to find their 'center' that has not yet been known.. a place of peace and love. One can now express that 'love' without fear of 'rejection'.
Of course, there will be all sorts of responses to the sudden 'surprise' knowledge that you are immanently dead. From denial to a thankful acceptance and peace.
I'd let everyone know. It will be a blessing for some, a curse for others.. let the chips fall where they may! Whats the difference anyway, for tomorrow, we die.