How much your home is worth depends on who's looking at it. Your home insurer will value your home in terms of the cost to rebuild it. A mortgage lender's appraiser will value your property in terms of the sale prices of similar homes in your neighborhood that sold recently. The property tax assessor may have a different set of criteria.
Due to recent changes in the economy, the market value of your home could be considerably less than it was a few years ago. However, don't be too quick to ask your insurance carrier to drop the valuation on your homeowner's insurance. This would save you money, but could leave you underinsured.