Lookups are the best way for us to leverage external data, but also leverage that data through the search function, filtering, etc. With that said, Lookups have severe limitations as they are currently tied to site collections. As a result, we need to repeat lists from one site collection to another. It would be wonderful if, just as companies move to a single Master Data Repository, SharePoint can have a single master lookup list that's used across multiple site collections. This would allow us to retain information in SharePoint and ensure it stays up to date with the master data more easily. Enterprise Information Management would be enhanced greatly.