So I've done several super complex Migrations using the Migrate API lately and I would love to do a workshop for developers on this powerful API, especially since it's made it's way into Drupal 8 core.
For this first one, we can use Migrate D2D and Migrate 2.6.x's new UI for doing an entirely UI-driven Drupal 6 to Drupal 7 migration (yes this is possible!). This would be great because it requires little (if any) coding usually and is a very common use case. One can transparently migrate users, roles, taxonomy, nodes and most cck fields from a d6 site to a d7 one in this fashion in a few simple steps.
This would be accessible to non-developers and be widely useful, but would at least allow me to introduce the basic concepts of the Migrate API.