90 - 100? I don't think so. Questing in WoD is pretty fluid and quick. You also gear at about the same pace. Not to mention you would be stuck with one or two 5 mans at the start which would lead to major burn out for me at least.
Questing has been, is and will always be the quickest way to level.
Maybe mixing in a dungeon here and there with dungeon quests would be optimal.
But if you don't like questing and prefer dungeons by all means do what you like.