Google is testing real estate and auto search sites built on Google Base and Google Maps, according to Shimon Sandler and Mike May (via Steve Rubel). The real estate beta was pointed out by Dustin Luther of Rain City Guide on March 22; he rightly cautions real estate startup Zillow that its days may be numbered as a result of Google's foray into real estate. "Right now, Google is seriously lacking in quality inventory. However, if the consumers go there (and they will), then you can expect brokers (and someday brokerages!) to follow with their listings," he writes.
The real estate search can be seen here. The auto search here. Steve points out that the Google Base logo is missing from both these, presumably implying the eventual launch of Google entities separate from Google Base.
