Regarding the Nephilim....
by Scott Alan Roberts
(New Richmond, Wisconsin, USA)
Cover for my new book on the Nephilim
I just completed a book on this very topic for my publisher, New Page Books - "The Rise and Fall of the Nephilim" - which releases in February of 2012. http://newpagebooks.com/?section=home&product_id=507
After many years of research and pondering, I am drawn to the conclusion that the Nephilim - at least in biblical terms - are the earthly offspring of the mixed parentage of human women and the "Watchers." However, the term "Nephilim" is confused with the Watchers, in that it is defined as "those who fell; those who descended; those who came down."
It is the Watchers mentioned in Enoch who did the actual descending, or "leaving" their first estate. And you are correct - neither the Watchers nor the Nephilim were angels.
I have concluded that the Watchers were members of the "Divine Council," as mentioned in Psalm 82 and other places throughout the Old Testament. They neither "fell," nor were they kicked out of Heaven. They were appointed to "watch over" mankind, then became embroiled with human women, bequeathing the Nephilim.
The crime of the Watchers was their teaching of forbidden knowledges to humans, and interbreeding with human women. For that, they were "locked in chains" to await judgment.
According to Enoch, the spirits of the Nephilim who died in the great deluge were forever bound to the earth, and it is the spirits of the Nephilim that became what we now understand to be the demonic caste. So, yes, the Nephilim are still here on the earth today.
As for the "alien connection..." it's a stretch for me to go that far, but I suppose it could all hinge on ancient mankind's perceptions of what they experienced.