There's a great interview of my dear friend Ben Hatke (blog) over at Parable:
S: Now, I hear you’re working on a graphic novel for First Second. Can you give us any hints on what the book’s about?
B: Yes! This is a full length Zita the Spacegirl story. The first of two books actually. A short Zita story appears in Flight Explorer, which came out earlier this year but this new book is a lot more involved and has a bit more action. It will tell how this young girl from earth ended up on her own in the universe.
S: Cool—I read that story in Flight Explorer. Is this your first full length graphic novel?
B: It is.
S: What aspects of the process have you found challenging so far?
B: The writing. Good writing is difficult in the best of circumstances, but I think what makes the creation of a really good GN so difficult is that, unlike a prose novel, when you make plot changes, or even small changes to a scene, it often involves redrawing a big pile of thumbnails (or worse, inked pages). And then your hand starts to ache just thinking about making the change and you might just decide NOT to change it and then, suddenly, you’ve given in to mediocrity.