I have just uploaded some NetBSD-current release builds with ATF merged in. These will ease testing to the casual user who is interested in this project because he will not need to mess with patches to the NetBSD source tree nor rebuild a full release, which is a delicate and slow process. For the best experience, these releases are meant to be installed from scratch even though you can also do an upgrade of a current installation. They will give you a preview of how a NetBSD installation will look like once ATF 0.1 is made public, which should happen later this month.Waiting for your feedback :-)
For more details see my post to the NetBSD's current-users mailing list.
Edit (Aug 20th): Fixed a link.