Viktor is already an incredibly strong mid laner, coming from someone who mains this champion, I believe that he does not require this type of buff. The extra movement speed does infact come from his Power augment, which obviously inst as much movement as boots, but it is something. Most mid laners would prefer the death augment anyway, so that doesnt apply. But this is where you have to think a little more logically about how cost effective his power is. The death augment grants up to 99 AP, almost as much as a DeathFire Grasp, without the active, for less than a third of the cost, and an extra 30% damage everytime you use your E (which in a way, is similar to, but not as strong as, a DFG). That kind of extra scaling, is beyond worth it, and for only 1000g it puts you way ahead in your lane early on. So thinking of that, along with Sorc Boots and 4 other meta items for mid laners (RoA, Rabadons, Liandrys, and Zhonyas), gives Viktor rougly 610 AP before Mastery Calcuation and Rune values. Whith that build youll be around 3k health, whith all that AP aswell... enough damage to be on par with other mid laners. Obiously the speed buff mentioned would be a very strong buff to his build, but it would almost make him too strong of a champion. His kit offers CC, aoe, poke, and DPS, fits into almost any composition.
Im open to any thoughts and any questions/concerns, but i personally believe that he is already STRONGER and does not require any buff. But as a main, i wouldnt mind one ;)