Great that the offline mode is finally back! It would be much more useful though if it would allow for synchronization of changes and conflict resolution on a node level.

MindMeister is a good tool, especially because of the possibility to use it on iPhone, iPad, several PC's, etc. - and always keep data in sync. The offline mode would add a great deal to the functionality supporting a proper sync mechanism.

Please consider implementing this feature which is especially targeted at your power-users who pays for the cloud service and the applications on several devices.