My poor blackboard1 only gets light use nowadays, I'm afraid. Coding examples are usually too large to put up there, all of my intricate diagrams are clarified with (judicious!) animations in PowerPoint, and my debugging gets demonstrated live on the projector screen. The humble blackboard has seen its role reduced in CS classrooms as the years have gone by.
It still has its place, though! Improvised diagrams go up there, such as when a student asks an unexpected question about a linked list. And pulling a struggling kid up to the board (during individual work time, not as some form of humiliation) can give us space, both mental and physical, to work through a conceptual problem together.
Of course, in more advanced CS coursework, we start veering back towards the mathematical, where the blackboard is still king. Well, maybe not the king anymore, but at least a Marquess or an Earl. Working through problems and proofs at the blackboard keeps the pace slower than a PowerPoint and gives the students that much more time to absorb the material, and asking students to write up the answers to in-class questions allows us to have class discussions around the results.
And there's one more place where the board comes in handy: harder labs, especially the kind that kids have a hand in designing themselves. I've found that my students naturally gravitate to the board when they need to brainstorm or work through a particularly tricky problem. Something about having all that space to think and try frees the mind. Paper just doesn't seem to do this same trick.
The blackboard may be dying, but it ain't dead yet.
1 Okay, technically I use a whiteboard in my classroom. I'd prefer a blackboard, but I don't get that choice in real life. But I get my choice here and now, in this very answer, and blackboard, I choose you.