From their site:
"The following assessors' information is provided as a service to the citizens of Stoughton. The information represents the certified valuations for Fiscal Year 2010. The date of valuation is January 1, 2009 reflecting sales and market conditions from calendar year 2008. Ownership records are updated on an annual basis, therefore, recent transfers of ownership should be researched at the Norfolk Registry of Deeds. No field card information is available over the telephone."
You might be lucky & have it updated in January 2010 or it might not be done till next year. Depends upon when & how they take their data feed from the registry of deeds.
Hope that helps,