@ Kluge ::
Thanks so much for posting that chart!
As a technical analyst, however, I'm inclined to take up a bearish sentiment on mining difficulty based on your chart. It looks like we hit a high and have fallen through longer-term moving averages, indicating that a lot of miners are calling it quits based on present difficulty (it's getting hard for most hobbyists to profit, I hear). But since I can't load those charts in a real trading platform and perform real back-testing and analysis on it, I won't swear by it...I could be wrong.
Your analysis is correct, but it ignores that cheap hashing power by a factor of 60x is about to be released in the next few months.