Vamos a volver VS. Volveremos. Which is more correct here? The English it gives is "We will return" and not "We're going to return" so I'd imagine the latter.
el-montunero - Yes, both constructions "going to" and "will" are used. In addition to "Vamos a volver." You could say "Volveremos" which means We "will" return. I think that, at least in Mexico, "ir + a + infinitive" is more common.