Lee Smolin is an interesting character. His book,
The Trouble With Physics went over quite a bit, and certainly along the way voiced some of my own sentiments and frustrations with string theory.
He has done a few talks in the interim, and there's a slide show which I found somewhat interesting, though I could not follow it in its entirety, entitled "Against Symmetry".
In it, he makes the case that pursuing symmetry to its ultimate ends, where all forces are symmetrical at high enough energies and "frozen out" as the energy lowers, leads to a few troubles, or at least possible incompatibilities with the likes of quantum theory, because it is by necessity
background-dependent.
Smolin said:
The search for a complete theory by the background dependent route
This has been the main pre-occupation of theoretical physicists the last 40 years. Is it now pretty clear that we have failed...
Smolin said:
(later on) The results to date:
The standard model of elementary particles: 20 free parameters
Its simplest supersymmetric extension: 125 free parameters
The number of distinct string theories that could reproduce them: 10500
This has physicists arguing for the validity of theories that cannot be disproven, to paraphrase.
I didn't know what to make of Loop Quantum Gravity, or Spin Networks (Penrose's favourite once upon a time), but I think I am beginning to see the value in the antisymmetric approach.