After a disk has faulted, the disk goes into a transitioning or an equalizing state. EMC uses different terminology to describe the action of repairing a faulted disk. Transitioning or equalizing times can vary based on the type and speed of the disk but your SAN utilization will have a direct impact on how fast a drive rebuilds. No where in Unisphere does it indicate a status or an approximate ETA time of when the drive is to complete.
You can check the state of the transitioning or an equalizing state but it is buried in the SP Collect logs. Once you perform an SP Collect, it is one large zip file. Expand the zip file and you will find more zip files. There is a zip file that ends in _sas.zip, within that file there will be SPA_cfg_info.txt or SPB_cfg_info.txt depending on which service processor you performed the SP Collect on. Within that file look for the information that shows you the status of the transitioning/equalizing process!