No - I haven't looked into this any further yet. To be honest, I have a very long list of features planned for MixEmergency (ordered by priority), and I don't think that this sort of thing would be a high priority feature (at this stage at least). Currently it would be possible to have some sort of text/image sequencer programmed using Quartz Composer and loaded into MixEmergency as a Quartz Composition overlay.
