You are correct that home prices in Van Nuys have dropped. The peaked in that 91411 zip code at about 600k are are now at 412 according to the Los Angeles Business Journal. Most agents gernally give commercial about 24 month lag to residential. And, the stimulus package and tax credits are affecting residential but not commercial real estate.
With that in mind, you can expect that it will be some months after this tax credit expires to see if residential starts to climb. Then you should see the commercial start back about 2 years later.
I recently showed some clients commercial property for a restaurant along Ventura Blvd. Three years ago there were no properties along the Boulevard for lease. They went as fast as they came on the market. Prices were over $4 per square foot with really high proven reserves.
I managed to find my client a property at $1.95 per square foot. And he had a number of properties to choose from in our search process which took about 3 weeks.
If you have any quesitons, please don't hesitate to call or email me.