Well, there are a couple of special abilities and spells that allow one to apply Sneak Attack damage to undead, so it might come in handy to be able to Feint them.
While I get the reasoning behind not Feinting non-intelligent creatures, I can argue the other side a little. Feinting is opposed by Sense Motive, which is Wisdom-based, which almost all creatures have. And if you think of it in Zombie Movie cliches (esp as D&D zombies are the slow, shambling original NotLD style, and not the 28 Days Later fast moving ones we all know to be ghouls), people are always feinting them, distracting them with quick, random motion and then stepping to the side and cracking their heads open.
So if a character was built around having an ability that made catching undead flat-footed worthwhile, I really wouldn't have a problem house-ruling it so that non-intelligent undead could be feinted. (If a creature didn't have a Wisdom score, then I would say he's non-feintable.)
Another thing, since the Zombie template has a -2 to Dex, if you animated say an elven acrobat with a 20 Dex, his zombie form would be shambling around with an 18 Dex, which is nothing to sneeze at. I don't know what that would look like, maybe similar to a drunken master, seemingly off-balance but always stepping just perfectly over unstable terrain. Or, imagine seeing a zombie shuffle across a tightrope. That's just funny to me.