Appengine is Google’s answer to Amazon’s web services (ec2, s3, …). I just signed up and got the following message: “Thanks for checking in! When space in the Google App Engine preview release becomes available, we’ll notify you by emailing…”
They have some demo apps. Also, the runtime or development language of choice seems to be Python…hopefully Ruby is next on the line.
Update: 11:14pm Got an Invitation to try Google App Engine saying my account has been activated. The account allows me to create 3 applications.