Our accountant told us last year that we really didn't need to worry about asking for a tax reassessment, it will happen without any action on our part. Hmmm?
A little googling and I find that this "letter" is not from the Government but a private company "offering a service". Turns out I can ask the assessor to reassess without any cost to me. In fact, our house is included in the current plan to reassess, it is automatically being reassessed (no fee). If we are not happy then we can request a review for the 2009 tax bill between July 2nd and September 15th.
We should expect a letter from the County Tax Assessor in June or July. :)