Here is a random collection of a few of the things I learnt last week in Korea.
Yuji Matsuda described experimental work on the iron pnictides which shows evidence [via a diverging effective mass] for a Quantum critical point hidden beneath the superconducting dome.
I am slowly becoming less skeptical about this surreal enterprise. Some concrete results that could conceivably relevant to experiment are being produced. Zaanen mentioned work by Gary Horowitz and Jorge Santos that produces a frequency-dependent conductivity that has some similarities to what is observed in the cuprates. [But, one needs to consider the alternative explanation]. I was disappointed that Zaanen ignored the work described in this post, claiming that interlayer "incoherence" in the cuprates is a mystery.
Henri Alloul recently posted on the arXiv What is the simplest model which captures the basic experimental facts of the physics of underdoped curates?
He is an experimentalist who has worked on the cuprates since the beginning. His answer is the one-band Hubbard model and Cellular Dynamical Mean-Field Theory captures the essential details.
Alloul's text Introduction to the Physics of Electrons in Solids has been translated into English. It has a particularly nice set of problems in it.
Aharon Kapitulnik gave a talk about Polar Kerr effect as probe for time-reversal symmetry breaking (TRSB) in unconventional superconductor. He has an instrument that can measure the magneto-optic Faraday or Kerr effects with a sensitivity of 10 nano radians! They have observed TRSB in Sr2RuO4 and the "hidden order" and superconducting states of the heavy fermion compound URu2Si2.
Non-zero Kerr effects are also seen in the pseudogap state. They can be interpreted in terms of TRSB or "gyrotopic"/chiral order associated with stripe order. [It seems the Berry phase may play a role there].
Isao Inoue, Marcelo Rozenberg and Hyuntak Kim gave talks about the emerging field of Mottronics: building transistors based on the Mott metal-insulator transition. A recent review of the field is here.
There was more, but that is enough for now...