Not true, slow is working now, at least to some extent. To observe the effect, go into a duel with a mace wielder who is using the slow attack at the appropriate level for the mace being used. Using a stopwatch and your awesome reflexes record how long it takes for your action bar to fill up to perform an attack when you are not slowed. Let the basher bludgeon you into a lethargic state

I obseverved a 35% increase in the the time to attack once slowed (probably not measured very accurately), making slow a quite worthwhile skill, better than bleed IMHO. Can someone else try this out and report their own findings ?