[Keneldil the Polka-dot]

I don't think much in the end result would have changed had Morgoth gotten to Men before the Elves. When Feanor proposed to leave Valinor he was told (I forget by who....Manwe?) he could not defeat one of the Valar alone. Adding Men to Morgoth's side means little. The Powers would still have had to come to Middle Earth to set things right. However, I think a whole lot in between might have been different (re: the point about Earendil).