Having a consistent api layer for hiding lob differences would be nice, and as Don stated the changes necessary to hook into the content repository are quite simple.
I think scalablity will be an issue, but on the plus side the CR's extensive api helps shield the packages that use it from most of the internal implementation. So, if we do some redesign to improve performance, the CR api will remain mostly the same, and there should be little or no change for the packages that use its services.
Overall, I think tying packages into the CR whenever possible is a plus, because it opens up interesting new ways of sharing data throughout the system via the use of a consistent interface.
