I've attended two parties on the estate, and I’m pleased to report the grounds have been beautifully restored, the fountains and waterfalls are again flowing, and the remaining guest house (the original mansion burned down in the ’60s) is adorned with beautiful original paintings of the master magician. There’s even a statue of Houdini now on the site.
Of course, Houdini never actually lived on the property. He and Bess rented a smaller house across the street that is no longer there. But he did spend time at the estate, which was then owned by a man named Walker, and when Bess moved to Hollywood in the '30s she held her parties and annual séances there, hence it came to be known as the "Houdini House."
You can read more about the Laurel Canyon Houdini home at Patrick Culliton's Houdini's Ghost.