Chris mentions in his FAQ post on 9.3 and Enterprise Guide that the new stored processes and other new metadata can not leverage all of the functionality in the new 9.3 release.  EG is nice to remind us of that fact when we open the SAS Folders view with the fancy warning message seen below.

So after contacting the SAS administrator everything will work fine. Wait a minute, what does the SAS administrator need to do to make this work?
Enter the new SAS Stored Process option 'Make Compatible'. This is available when you right click on a 9.3 Stored Process from SAS Management Console.
SAS will generate a couple of messages for you to modify the stored process to make compatible with the prior version. The first one I received stated "Can only convert stored processes which run on a specific type of logical server". This corresponds to the Server Type selection in the Execution tab of the Stored Process properties. So we need to switch from 'Default Server' to either the Stored Process server or the Workspace server.
After modifying this screen, I tried the Make Compatible option once more. The next error message was 'A source code repository has not been set'. In 9.3 stored process code can be stored in the metadata itself, rather than as a separate .sas file located on the server somewhere. This is brand spanking new functionality that prior 9.2 based releases wouldn't know the first thing about. So I went back to the Execution screen (captured above) and changed the source code location to point to a source code repository and file on the server.
Now after clicking Make Compatible one last time and receiving no warnings (or confirmation messages), I jumped back over to Enterprise Guide, clicked the refresh button on my SAS Folder view, and ran the stored process.

This situation occurs not just for Enterprise Guide but for Add-in to MS Office. The most recent releases of both of these products was before the SAS 9.3 Integration Technology release. But as Chris mentioned in his post, the next version of EG and Add-in to MS Office will be fully compatible with all this new stored process functionality.