Uhm, honestly I don't think they'll give him ears like trist's but a slightly modified version, remember he's got a hat so they'll look more like Lulu's perhaps?
I wonder how a Yordle looks like when he's become corrupted by evil... though on Veigar's case I think he's supposed to look more like Vivi from Final fantasy 9 than as a yordle per se... think of it like a kid dark mage... still it'd be pretty cool if instead of shadow in his face we could see some black fur like a lot of interpretations out there
His clothes I hope they change, currently he's not wearing anything... he's got this sort of robe with a huge belt? unlike some of his skins where he's actually wearing something, though I understand he's supposed to be just a mage but there are some cool outfits veigar could wear while keeping certain shapes in check, like the high neck and robe-belt feel. He needs clean up too like removing the hat ponytail and reducing a tad the belt in his hat as well but most importanlt, please, PLEASE remove the tutu-like skirt ._.
also, for reference an image of Vivi, doesn't he reminds you of someone? http://img3.wikia.nocookie.net/__cb20100818231822/finalfantasy/images/2/2d/Vivi_Ornitier_character.jpg