Timely post. Been thinking about this, have had a couple of requests too.
How I've seen hybrid photography defined by some is that the final delivered product is looks like a slideshow of stills with video clips inserted. Have to say it doesn't really appeal to me, and the limited examples I've seen tend to look 'cheap' and somewhat dated in feel. This approach seems to be stills-priority, and video clips are grabbed where appropriate/possible, so they're not really shooting to edit a highlight video, but individual standalone clips that will be inserted in a stills slideshow. I think I'd personally prefer a video-priority approach, with stills for stuff which don't really benefit from being in videos (group photos, etc)?
I guess it really depends on what the client really wants. I imagine while some actually want a set of stills for printing, in addition to a video, others may actually just be interested in a 'hybrid product' as defined above.
Anyway, first thoughts are that we'll definitely need to communicate clearly that covering an event with both stills & video deliverables as a single shooter means that the overall product will be a combination of both. E.g., 50% stills + 50% video (or whatever ratio client would prefer) = Final Product (100%). It's a bit obvious, but I suspect clients may tend to expect 100% stills + 100% video = Final Product (200%).
E.g., For a 2-hour event, if I might normally give you a X min highlight video, in a 50/50 hybrid situation, I may only be able to give you 1/2X min highlight video, as the other moments will be represented in stills instead.
It would probably also be helpful to work out beforehand if the client has moments which they definitely want in stills and which in video.