Interval Partitioning in 11g and index creation

Prior to 11g when we wanted to add a new partition for a new months data for example, we had to run a script to create the new partition, and prior to inserting any data we would set the index to unusable and then rebuild subsequently.  What I would like to know is what happens when we use interval partitioning?  Is the index automatically created in an unusable state as the partition will be automatically created as part of what may be a bulk insert, in which case we would not want the index to be usable as this will