I'm about 90% sure I don't want to add an LCD to this project - I'm really in a perennial state of screen fatigue, and while it could certainly be handy, I'm choosing to go as analogue as possible for this project. I also like the idea of having no clue what my pictures like until I get home to "develop" them.
But if there's anyone out there following this project who wants to recreate or build upon what I'm making, you could easily add a screen at this point in time. I have one of those (I believe) 3.2" or 4" screens that slides right down on the IO pins. From my little mockup, it does add some additional depth but it's really not too bad.
With a nicely designed backer and the RPi case epoxyed in place, you could have a really snug and safe fit on this, and there's already tons of code out there for a touch-screen digital camera interface of this size. I'm tempted. But I really hate screens.