compatible with Ubercart?

I'm interested in Ubercart compatibility, too.

I had this requirement for Drupal 7/Ubercart 3. Managed to create a module that gives some level of integration without requiring changes to either Shared Email or UC Cart.

It uses hook_checkout_pane_alter to intercept the checkout form callback (for validation) and hook_menu_alter to intercept checkout completion, where it creates the new user with duplicate email address if necessary before UC Cart does anything. With this module enabled a new user will always be created during anonymous checkout, the order will never be attached to an existing user.