I wondered why I still couldn't find Google Base listings last week. Then I got confirmation that I was not alone in wondering what happened to the promised Product Search switch from Froogle to Google Base. Brian Smith posted a comment about it on his ComparisonEngines.com blog on Thursday.
Back in September, Google had told eBay PowerSellers it would roll out product search on Google.com during the holiday shopping season - the search would bring back results exclusively from Google Base listings.
Currently if you do a search on Google.com for "ice cream maker," you'll see something called "Product search results for ice cream maker" at the top of the search results directly underneath the sponsored links. Clicking on the hyperlink still brings you to Froogle results, not Google Base results.

So where do Google Base items show up? When I go to Google.com to look for Google Base, I don't even see it listed among all of Google's properties.
If you go to http://base.google.com, you won't find a search box. You have to click on a type of item, such as "Products," then you'll be taken to a Google Base search page for that kind of item. This is the page for Products search.
Once Google Base is integrated into Google.com search results, it should be pretty powerful. For now, we'll all have to wait.