This is so cool and so needed. I think the key will be for them to properly manage the easy cases ($200) vs the hard cases ($750) plus so customers don't feel bad about it. I often work with people who think that their migration is going to be easy, but moving very large DBs or DBs with lots of custom tables or when you need to splice user or post tables or keep a dev site from sending emails/etc, it can get very complicated quickly.