I think a good feature to add would be some sort of kiosk mode that could be used during a wake or reception by just putting a web browser on one of your pages and it would rotate through photos, guestbook entries, etc. like a slide show but would drop in to the guestbook with a mouse click and go back to the slideshow after the page went idle for a while.
Another good feature would be a way for people to buy coffee-table books of a site to save as a personal memory. I'm certain with some effort and partnerships with a publisher, you could create a well designed book automatically from the data you have. I put together a video montage of my father after he passed away and having something tangible that you can have of a loved one is always comforting.
Finally as a way to generate traffic, I'd consider building some killer example sites of celebrities as soon as the news breaks of some celebrity's passing.