Lot of interest in the book of Enoch right now. There's debate as to whether Jude quoted from the book of Enoch... but even if the Holy Spirit cited the book that doesn't raise the book to the level of being inspired of God. Paul quoted from several Greek writers - Aratus (Acts 17:28), Menander (1 Cor. 15:33), and Epimenides (Titus 1:12), yet no one today contends that those works were inspired by God. As far as nephilim being present today, I seriously doubt there are given that none are verified as being present in the bible after the flood (note: just because people are "giants" doesn't mean they were nephilim).