Jim - You are correct. If yesterday was the first 80 week low that the next Hurst 4.5 year low works out to 2012.22 (approx March 24, 2012).
That 2011.45 date, however, will be the next 'major' Armstrong cycle low (and the likely position of the final 40 week Hurst cycle low prior to the bottoming of the 4.5 year Hurst cycle).
It is the Armstrong sub-cycle which immediately follows the 2011 date that will fall in line with the next Hurst 4.5 year cycle low .
Note that two of the above Armstrong dates (9/2010 and 3/2012) have obvious correlation to future expected major Hurst cycle (next 80 week and 4.5 year cycle) dates. I would also expect the above 6/2011 Armstrong date to wind up also being significant for Hurst as was seen back in Oct 2002 (recall that Oct 2002 was the prior 'Price' low AND a 20 week Hurst cycle low - this was also the prior major Armstrong cycle low.