I believe that was God in the bush not an angel.
Having watch The Ten Commandments repeatedly I would also prefer to believe that it was God in the bush.
However, the traditions entwined in the narrative differ: the J Tradition has God manifesting himself to Moses; the P Tradition has an Angel, God's surrogate, appeared to Moses to save God's transcendence.
The early Fathers explain that it was indeed God, the Word pre-Incarnate, who appeared to Moses, which "jives" because the Son proceeds from the Father from all eternity and therefore is relatively "subordinate" to the Father; He is the Son from all eternity who speaks for the Father as his "messenger" (which is what "angel" means) being in fact, God's own pre-existent, eternal Word.
I find the Patristic view the best Christian interpretation of the text.
-Theo
It says that God spoke out of the burning bush.