Okay okay some credit must go to the lovely Chocolate080403 for mentioning it first but an Oz spinoff would be an amazing opportunity not only to flesh out Zelena as a character who, as I think we call on agree on as a fandom, was greatly underused but to use the incredibly rich Oz mythology. So much was lost in the backstory Scarecrow, Tin Man and Lion, WWotE etc.
Now I know some might disagree on returning to Oz (stealth pun) because of many things: it just wouldn't work, Glinda's not in the picture any more "insert your preferred use of excuse here" but I actually believe it could work...and I have evidence...kinda!
1) If A&E wanted to go back to Oz, they could. Like with Wonderland, the Oz books feature a multitude of stories of Dorothy's adventures in Oz, it would be an amazing opportunity to put their twist on the Oz tale because there is SO much to work from.
2) I know what you'll say "Broke Boy they've already gotten rid of Glinda, The East Witch isn't Wicked and Dorothy is gone, the story is told". No. Glinda in the Wonderful Wizard of Oz doesn't actually play as big a role as many think. In the Wonderful Wizard of Oz the one who greets Dorothy on her landing in Oz is the Good Witch...of the North, Glinda wouldn't need to be there. Also, The East Witch; piece of cake. Don't turn her wicked, she doesn't need to be. It was speculated that L. Frank Baum (writer of the Oz books) had intended not to have Four Witches of Oz...but Eight.
Let me break it down; as we all know North and South had Good Witches and East and West had Wicked Witches. However later on comes Mombi; the Wicked Witch of...the North *gasps and screams* I know. Mombi got beat down by the GWotN and Baum mentioned a WWotSouth who got taken out by Glinda. However he died before he could introduce the Good Witches of East and West. There was supposed to be a Wicked AND Good Witch in each direction. See we can still have the Good East Witch and then introduce the Wicked one later on. Also we could have Mombi come as a big player in the Oz power game (in my fantasy she'd be played by the indomitable Jessica Lange who put a sexy spin on the "lowly hag"). Zelena's beef with Dorothy could also account for what she did all that time Oz!
3) Also, I was really upset that the Scarecrow, Tin Man and Lion were left out, another trip round Oz could introduce them and A&E could use some more of the Oz mythology Tik-Tok, Gayelette, Princess Ozma and King Pastoria, Jack Pumpkinhead, Jellia Jamb, Polychrome, Nome King and Patchwork Girl.
I still have more ideas and stuff but I don't want to go overboard on you but I honestly think this opportunity is too good to pass up. Well...thoughts!