Solo apps can be designed as "rich clients", encapsulating both presentation and business logic. I would not use it this way. After finishing their quick tutorial, it occurred to me how easy it would be to use Django for a controller, serving up XML which OpenLazlo can then consume and present. In this way, OpenLazlo would take over all the duties usually performed by Django Templates and Forms, including client-side validation. What you gain, is a rich event-driven UI that is exceptionally easy to write and understand, developed in a fraction of the time as the equivalent in any AJAX toolkit you care to name.
I hope to play with this in the future, and when I do, I will post some examples of Django/OpenLazlo integration.