When a spawner spawns mobs with custom tags using the "SpawnData" tag and the "Rotation" tag the second Double tag doesn't work. The mob is always rotated the same way.
How to reproduce
-put this in a command block
summon Pig ~ ~ ~1 {Rotation:[70.0,0.0]}
-as you can see the pig spawns with the default rotation
How to reproduce using spawners:
-Create a custom spawner, spawning rotated villagers.
-Set their health to 0 to make them despawn immediately.
-You will notice they will always look to 0 (south)
Related issues
duplicates
Comments

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
(Automatic Message)
confirmed for 1.6.2
Confirmed for 13w36a and b Even with spawning mobs using /summon
Is this still a concern in the current Minecraft version 1.7.2 / Launcher version 1.3.4 ? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
yup

Did not test in spawners, however is still true in 14w21b.
Here's proof:
http://youtu.be/FmQva1Vr4RA

Still present in 1.8 (I tried pigs and horses, with the same effect).

Fixed in 1.8.1
related to [MC-15515]