Today I got my 2013 assessment. Market conditions have improved a fair bit recently, and I'm probably not even underwater on my mortgage. I expected that the assessed valuation would pop back up to about last year's value, and I'd have to send them another letter. To my great surprise, the assessed valuation is exactly the same as the adjusted 2012 valuation.
This will save me about two grand on my property taxes this year. Thank you Ron Thomsen.