While a project name change alone isn't too important, they are also changing the API, libraries, D-Bus addresses, and everything to reflect the new "udisks" name. Yes, everything. Any application that is dependent upon DeviceKit-disks / udisks is going to need to be revised to incorporate the name change. DeviceKit-disks and DeviceKit-power can already be found in Ubuntu, Fedora, and other Linux distributions, so there may also be some pain in the upgrade path of switching over to using the newly named udisks and upower packages. Hopefully though the transition process will go smoothly.
This announcement was made on the DeviceKit development list.