Read Fr. Z’s post – it might help. It’s not about Limbo, per se, but about Benedict’s method:

On a personal note, years ago when I worked in the Palace of the Holy Office, a couple days after he released his instruction On the Ecclesial Vocation of the Theologian I encountered Cardinal Ratzinger in the hallway and had a pleasant and very fruitful chat with him. I told him I had read the document through a couple times and he, with his characteristic kindness, asked my opinion about it. I responded to his surprise that I wasn’t satisified. "Why", he asked. I said, "There are quite a few pages there, but nowhere do you identify who a theologian is." He regarded me for a few seconds and then said, "Why don’t you tell us. You are working at the Augustinianum [the Patristic Institute literally across the street from the Holy Office building]. You are studying St. Augustine. Find out what St. Augustine thought a theologian is." That became the basis of my first thesis and I have him to thank for it. My point is that the Pope approaches the issue of theology and who the theologian is with great humility. I give this personal example as a tiny flicker of light to illuminate his own theological method.

Benedict XVI is always taking the time to interrogate the past about today’s burning questions. In helping me to a thesis topic, he did what a professor had done for him when he was young as he steered the young Ratzinger to go back to Augustine to explore what was meant by the "People of God", a much discussed question of those years. Even in his Regensburg Address, the Pope uses something of the past as a crowbar to pry open the difficult questions we face today.

He pries and prays and then pronounces.

This more than likely why, in his present role as Supreme Pontiff, he did not breathe even a single word about limbo in a sermon to the Theological Commission. He didn’t even mention it as something they had studied!

He is going to pry and pray before making a pronouncement and he wants everyone else to do the same. Let us not forget that he also told those theologians present (as well as other theologians in the world together with himself) that theological pronouncements must be subject first to silence and God’s will, rather than the bombastic pressure of the world’s expectations.

Also check out Zadok’s post, which concerns Limbo specifically.