Think "supply and demand"....Mill Valley values will not necessary track the same as all of Marin or the Bay Area in general. Southern Marin, including Mill Valley, historically aligns with prices in the northern quadrant of San Franciso--and usually trails those trends by several months.
A chart of average Marin values for the past 50 years will show a distinct increase year after year except 1990-93 when there was a leveling of value and then the current market with a decrease. The amount of price decline has differed neighborhood by neighborhood, so it's tricky to look just at the averages. If you're trying to decide whether to sell now or wait, it's important to look at the properties for sale now and recently sold in your neighborhood. Then, ask yourself honestly, how does your house compare. Homes with "flaws" (like no yard or difficult access) and those that need a lot of fixing are taking a bigger price hit than they would have in 2005 -6.
Unemployment and foreclosures are lower in southern Marin than most places in the state so this bodes well for a quicker recovery. Prices and demand seem to be improving this spring both in San Francisco and Southern Marin, so depending on a seller's motivation and the specifics of the property, it could be a good time to sell. A recent sale in the Scott Valley neighborhood garnered 12 offers and the selling price exceeded the asking price by $200,000. You're lucky to be a home owner in Mill VAlley. maryann