Divine Storm has not had the correct animation since the launch of Classic WotLK. Previously, I have been saying that the animation for the spell we have is the MoP animation.
I did a side-by-side of the live, WotLK Classic visual, and the old, Cataclysm visual, Version 4.3.4 (15595), which is the original WotLK visual.
The animation appears to actually just be missing 1 of 2 spell visual effects that occur simultaneously. The missing other part contains the textures that make the spell effect linger with some awesome lightning for around 3-4 seconds.
Watch the rune that flashes above my character in the first video:
Notice the 2 runes that flash above my character in the Cataclysm client’s: