We rolled a D20 again If the Dinosaurs were this lucky...

We would be running around their skirting boards.

http://www.theregister.co.uk/2012/06/15 ... rish_miss/

I'm not worried. We only have maybe a few decades, a century at most, until we will be able to protect ourselves from any asteroid. There's not much chance of humanity getting wiped out in the interim.

That's not how probability works. Just because there is a 1:1,000,000 chance of something happening on a given day, does not mean it's not going to happen for a million days. It could happen tomorrow. No prorated refunds either.

Plus, we have insufficient data to make the above prediction as well. Everywhere we look, we see more stuff floating around us, be it co-orbital or eccentric orbit comets and et., and that does not include the possibility of new stuff being swept into the solar system as the Sun cruises thru the local cloud.

Anything we predict is a semi-educated guess, or wishful thinking.

You are right, that anything we predict is an educated guess, but then you could say that about anything - including the prediction of a given chance that an asteroid will hit the Earth. In any case, barring a world war that puts back civilization, at the current level of tech growth, we should be able to protect ourselves within a few decades.
Also, the chance of being hit during the next few decades is much smaller than the chance of being hit during the next few millenium.