I'm somewhat "conflicted" with regards to Susskind. I'm a physicist, but I don't know much about string theory or LQG. As a bystander to the "Not Even Wrong" debate, I agree with Smolin's points about falsification and predictions being an essential feature of a physical theory, thus, on a personal level, I took Smolin's side (').

Then, couple of months ago I found the Susskind lectures on iTunes, watched and enjoyed many of them. (They're aimed at a general engineering audience, but I still found portions such as General Relativity illuminating.) Susskind is clearly a physicist of the highest caliber, the last time I heard such first-class lectures was when I listened to the Feynman MP3s during my freshman year. So on one hand, if Susskind says these ideas have merit, they're probably worth taking a look at. On the other hand, there are so many other interesting areas (in physics and elsewhere) where I feel something tangible could come out of that I am still ignoring string theory for the most part. I should note that I'm not very representative in this regard, as Smolin notes, most theoretical physicists at top U.S. universities are string theorists. It's interesting that here in Hungary, while the graduate school offers some courses on string theory, I don't know anybody pursuing related research. Most theoretical/particle people are doing SM/QCD related stuff, which is clearly a cultural thing here.

(') In reality, falsifications and predictions are a tricky business in physics with people making implicit assumptions, circular logic, estimated error bars, etc. --- I think that non-physicists' view of this is similar to my view about police work based on CSI:NY.