Torches usually slant in a certain fashion, but in almost all of the 1.8 snapshots, torches are in the same shape as they are when placed on the ground. This applies to redstone torches as well.
Screenshot 1 is of a torch in a 1.7.10 world (Dataless822's Survival World)
Screenshot 2 is a comparison of normal and redstone torches on a wall and on the ground.
I'm pretty sure this is intentional, not a bug.