Are Google, Yahoo, etc ready for the Enterprise or just single users?

Do these entities really understand the requirements for IT within an enterprise space?

Yes they create neat stuff and fast...but is it built with the proper industrial strength required...or just hacked to get it out there?

I quote from another source "A business like google, amazon, ebay, yahoo publishes an API. Let’s you build a business around it. Then turns it off."

Your thoughts?