I'm so super very happy I can't hardly even say! She's clad head-to-toe in Magister's.
Her weapon is The Headless Horseman's Baleful Blade because it has just a delightful glow, don't you think? Also, it's a plain sword at its core, which is something I was after. Mages shouldn't carry overly fancy swords, I think. Also, there's some filagree at the base of the sword which somewhat matches the pattern of the Magister's robe.
I attempted to use Dalaran Sword, because it's a classic sword—but with purple in it—and also because that's the town Abethany calls home, but the transmogrification process wouldn't let me.
Her off hand is the Chronicle of Dark Secrets. Don't you just want to open it up to see what secrets it hides?
It's altogether a rather smashing outfit, don't you think?
All 'n' all, I'm very quite super happy with transmogrification. It's the thing I was most looking forward to in Patch 4.3!