Great read about the synthetic diamonds. I really hope that's true, I've been following the limitiations of silicon semi-conductors for a while and they are very near the limit today.
As for natural gas, sure it'll rebound. Nobody is predicting sub $2 price will last more than a year or two. However, the amount of supply that could be turned on within a 12 month window is massive. You won't see north of $5 anytime soon, and I'd say it'll have a very hard time getting up to that in the next ten years. Demand may increase, but there is massive supply ready to be uncorked with minimal effort.