Me and a freind had a really big argument over this card the other day! He thinks that when you play a land from the top of your library with this card, it doesn't count as your land for the turn, so he ended up dropping like 5 land in a turn once! That's what started out argument, I thought that it would count as your land for the turn!
{Oracle of Mul Daya}
It counts as your land play for the turn. He can play a total of two land that turn because of Mul's ability but it still counts as playing a land.