A while back I was in a Haukke Manor run with a few FC mates, I was ACN at the time because I was only lvl29 but one of our members came as SCH. A pink book dropped that had no MND on it whatsoever. Not realizing it, both myself and the SCH rolled need on it. I lost the lot, and then the SCH realized there wasn't even any MND on it and apologized for taking the book. It is untradeable and there was no way to give the book to me (would have been a nice upgrade for me at the time).
Edited, Oct 14th 2013 10:07am by Canadensis
From what I recall, Stone Vigil is the first time ACN encounters the split between SMN and SCH. I've never seen the Haukke Manor weapon, but up until then, every book I had seen had both MND and INT on it. The books available on the Market Board also have both INT and MND up until level 50. At level 50, both the Deus Ex and Erudite's Picatrix books are specific to SMN or SCH. It is similar with armor. I didn't see much mage gear in SV, but I know the mage gear is split between healing and DPS in the Darkhold: Harlequin for healers, Coliseum for DPS. Healers, whether WHM or SCH, cannot Need on Coliseum gear, and BLMs and SMN cannot Need Harlequin gear. The Market Board armor starts splitting out around level 45 as well. The one exception I've seen so far is the Warlock's gear in Wanderer's Palace.
Basically, while SE gave ACN 2 choices of job, you are more or less forced to focus on just one by level 50 - just like everyone else