This change is needed in order to implement the calendar functions that are available with iOS 4. The addition of calendaring will provide the ability to schedule maintenance reminders etc.
Also new with the release was the addition of lots of maintenance categories. There have been many requests for this enhancement and this is just the first step.
These new categories will allow AutoLog users to better organize their data. In a future release the concept of grouping items by their respective invoice will be implemented better then it currently is today.