Have heard news that Esri's road-map may include the decommissioning of the raster catalog. Can anyone confirm / deny this? Can't find any news articles online but we need to future-proof our systems architecture and we do not want to spend money purchasing Image Server. We have some great time series datasets of historical mapping using raster catalogs so I'm hoping my intel is wrong!
Here is the process you'll need to update your Raster Catalogs to Raster Mosaics. I use ArcGIS 10.1, you might need to look up the corresponding links in the appropriate version. I'm not sure what special surprises you will experience with your data, so make sure to have some Quality Control checks before and after each step.
Note: Raster Catalogs are able to be directly imported into Raster Mosaics. In which case you can skip step 1. Although it might be more beneficial to first turn them into Raster Datasets and then import them into the Raster Mosaic considering the current lack of support for Raster Catalogs. List of supported raster and image data formats