He starts the following quests:
Grif Wildheart is very likely to be the dwarf hunter from the opening cinematic. They're both dwarf hunters, have the same hair color and hair/beard style. Also, the fact that he's in Dun Morogh (a snowy area, just like the cinematic) helps support this beleif. Not only is this dwarf in the opening cinematic, but he's also in a ton of artwork, including the original WoW box cover.