Zillow better watch out: The latest thing to emerge from Google's barrage of launches this week duplicates one of the Seattle startup's most valuable features.

Google is now offering an instant mortgage quote service that instantly connects lenders to buyers, and provides useful tools for comparison shopping. It also instantly estimates house values (a Gestimate?) provided by IntelliReal.

The mortgage rate feature showcases new "comparison ads" that it's launching in a limited test, selling space in free tools that consumers may use before making big-ticket purchases.

UPDATE: Google Maps is also adding Zillowesque real estate info. From the announcement:

First of all, we've made it easier to find real estate listings. Now, you can simply select "Real Estate" from the 'More' button on the top right of any Google Map to discover listings. From there, it's a simple matter to refine your search using the left hand panel - price, bedrooms, bathrooms, and so on. Of course, you can still pan the map to search for the perfect neighborhood and it'll automatically update with more listings.

I wonder if comparison ads will muddle -- in consumers' minds -- the information found by impartial search algorithms and paid placement. It may be handy if you are rate shopping, but it's no longer the results of an objective search engine.

Sound like Google's becoming more of a decision engine. Maybe it's time for Microsoft to buy Zillow before it loses zest.