Yesterday our customer was (rightly) getting nervous about not having seen a build yet, so the team committed to producing a build today and followed through with flying colors. I'm still getting some questions along the lines of "why build when we know all the functionality isn't there yet". If we can get the build process somewhat more automated I think these questions will go away. Our customer really likes being able to see incomplete functionality so he can make changes before we've committed a lot of time. QA also likes being able to see the product earlier in the cycle so they know their tests are accurate and complete as well as giving earlier feedback. All in all just the way agile should be working, we just need to straighten out some kinks.