I finished Wicked(the book obviously). It was awesome. I need to see the Musical. It makes me sad that Fabala died, and that Dorothy killed her, but I knew it was gonna happen. Dammit, Elphie is sooo much cooler than Dorothy. And the bit about all of Dorothy's traveling companions was interesting. I never would have guessed the origins of the Tin Man even though it was all right there in front of me.
But my biggest question, surprizingly, is not about Dorothy, or Glinda, or even Elphie. Where the hell is the Wizard from? That No Irish Need Apply thing threw me for a loop. It sounds like our world, and Dorothy's, but how does he have magical powers and such if he's from there? Also, I totally saw the Elphie/Wizard connection before it got revealed because she can only kind of read the Grimmerie. It implies that she's half-blood from where ever the wizard is from since he can read it no problem. And hence she's green.
I just really want to recommend this book. Read it. Enjoy it. Love it. Don't worry when it takes you several weeks to read despite how cool you think it is.