Google's app-engine applications for Google Apps for domains

What is game changing about this is that 3rd party application developers now have access to small businesses that google has signed up on its free e-mail for domain platform the google apps. So suddenly a web 2.0 developer can go beyond orkut applications on a relatively non-monetized social network and start building applications for paying businesses. It is likely that the leap of faith required to sign up for an application that exists on Google Apps is far lower than resistance to sign up for an entirely new application.