[Update 09/09/2013] I mentioned below that we'd make our scripts available for setting up BPF.
The major theme of the next release of Migrate on Drupal 7, version 2.6, will be developing an infrastructure to make it easy for migration modules such as wordpress_migrate and migrate_d2d to build user-friendly interfaces for importing content, based on step-by-step wizards. This work includes not just adding a wizard API, but also presenting a simple interface for non-technical users to run and review imports while still giving migration developers all the information they need. Initial work has begun and is available in the current -dev releases of Migrate and WordPress Migrate (with some more rudimentary work in the wizard_api branch of migrate_d2d). The API is still in flux, so if you're interested in experimenting with this it will be important to update the modules in sync for the time being.
Last week the Acquia Engineering team assembled in the office for a week of brainstorming, coding, and fun.