In Rice 1.0.x, client applications connected to the registry directly through the database layer. This had the advantage that the database, being a fairly high availability service, is usually online and operational when a client application starts up.
Now that client apps connect through a SOAP service, that means that the entire Rice Standalone Server needs to be online (since it's not possible to just run the registry as an independent app) in order for client applications to come online. Considering the number of pieces in the Rice standalone server, this is going to be a problematic requirement for some I imagine since they may need to do maintenance on portions of the rice server that really have nothing to do with the registry and that will adversely affect other applications connecte to the bus.
A client application should really be allowed to come online in these scenarios, they just might not be able to function properly but would begin functioning properly once the bus comes back online.