My understanding (and I'm happy to be corrected) is that feature and security updates will continue to be provided for Ubuntu.
Ubuntu Pro's update badgering seems to allow for updates to be provided for packages that aren't part of the base distro makeup - like packages that are held in non-Canonical repos.
For home users, Ubuntu Pro is free... for now.
I don't think it's anything horrendously bad, but the way it's been rolled out is pretty fuckin' far from good too.