i'd have to agree that prices haven't come down as much as they will in the Tahoe Basin. With the California and Nevada real estate markets having gone down by 10-30% in many areas due to speculation, I haven't seen that decline in Incline Village yet (some areas in the Tahoe Basin are down a little).
A majority of Tahoe properties are investment properties (I've read as high as 70%), many used as rentals to help pay off the mortgages. With ARMs coming due, many are finding their primary rates increase (and potentially their vacation homes too!), and more people are willing to part with their vacation home than their primary home (esp. if their primary home is down 10-30% and their vacation home hasn't come down as much).
Add that to warmer winters causing shorter ski seasons and Tahoe historically being a winter attraction for those coming by car from the Bay Area and the Sacramento Area (have you seen gas prices recently?! ... And I doubt that the price of gas is going to be better this winter!).... there's definitely going to be a lower occupancy rate causing these mortgages payments to be coming out of pockets of the property owners (e.g. negative cash flow instead of that once positive cash flow).
Other destinations that are reached by flight are becoming more affordable in comparison esp. for the younger crowd that might not have been packing in 5 to a car. Why party in Tahoe when you can party in Aspen, Jackson Hole, Whistler Blackcomb, etc.
Of course those that live there will continue to live there and those that have been in the market for 10+ years have enough in the house (assuming that they didn't finance money out of the house) to keep them as profitable rentals for some time to come. If you plan on buying, definitely wait out this winter!