They have ended up with a dP_8 singularity (the most complicated del Pezzo surface). Their idea is that the Standard Model is everything there is - which is why it comes from a single D3-brane probing a particular singularity - and everything else is just quantum gravity encoded in the compact part of the Calabi-Yau manifold.
Today, in a
with David Morrison, Matthew Buican, and Dmitry Malyshev, they embed the singular picture into a compact Calabi-Yau manifold that they can explicitly construct: this manifold had to satisfy rather strong topological constraints that they explain. They also require that only the right hypercharge which is a particular U(1) combined from the U(1)'s in the original
- U(3) x U(2) x U(1)7