The ability to access Domino applications without a server, or needing to know where the server is. Think Domino via Distributed Hash Access, either to a Notes client, ICAA client or to a Domino Server.
To support this, handling cross certificates will need to be considered, options could be:
-allowing an open method so the cross-certificates don't need to be pre-populated in the Domino Directory
-an open certificate created by IBM specifically for this feature
-sharing one half of the pair's key within the distributed hash link
Expand the author and reader names fields by selecting the allowable certs to a document, especially if the source application's host's key pair hash is shared. This could take the form of a drop down or selection of the known certificates from the Domino address book.