A rather devastating critique
See source

This stuff has been known for a century or so. The basic facts about the E8 group have nothing to do with problems that physics has been solving in the last 50 years: they are just a part of the mathematical background that high-energy physicists are supposed to know. Garrett Lisi remembered something from math classes he was taking 15-20 years ago but he has forgotten virtually all of his physics classes. The way how he combines his spotty knowledge with ambitious claims mimicks the approach of thousands of other "amateur Einsteins". He was just luckier because a journalist has endorsed him.

yeah, what he said-

Sorry, should have pointed out that is in the thing Djezes sends us to.
Tell you what though, looking round the web have been amazed at how many mystics, new agers, druids, warthog taxidermists have jumped on it to say they knew it all along. Whatever 'it' is. I made the mistake of accepting New Scientist as an authoritative source of balanced science news. There is, nonetheless, from what I can see a glimmer of interest to be had from 'theory'.

The theory of everything? God did it.