- Dodgeball - I'm using Brightkite. Think of it as "location-based Twitter". The user base is no where as large as Twitter. And it will never replace Twitter. But it's a neat tool that has led me to meet at least ONE interesting person in real life.
- Google Catalog Search - There's not much need to search online catalogs. Any company with a catalog has figured out how to put together an ecommerce website by now (hello, 2009). And if you want to search multiple, you'll use comparison shopping engines. Though these leave a lot to be desired. But so do most ecommerce websites.
- Google Mashup Editor - Nifty and cool for developers. Unknowable for the rest of us. Plus the mashups that came out simply added to the aggregation problem. We need better filters, not ways to combine and create more.
- Google Notebook - I used this for a while, but now I have Evernote. Which was coded by God. Or at least a minor-deity.
- Jaiku - Surprised it took that long. Hi, Twitter.
- Google Video - This really isn't "killing" as much it is putting the YouTube purchase in full play. No need for two identical services owned by the same company.
The disappearance of these tools will be -- and in fact is -- a non issue for most. As you can see, their are better tools that exist in the same niche as each. Smart move on Google's part to recognize that fact. It's a big internet.