He is specifically stating that as of right now if you want to use Google AppEngine to send email you need to have a Google Apps account.
So after today (no more free accounts) if I want to set up example.com as a domain to send email from on my Google AppEngine webapp, I will have to fork over X amount of money a year to have those essentially non-existent users that are valid mailboxes.
> Please note this change has no impact on our existing customers, including those using the free version.