I actually like this fight -- a lot. Let's break down the essential stats, shouldn't be hard being a Taijutsu-only fight.
*Minato has greater speed (with or without shunshin).
*I'd say their hand-to-hand taijutsu is roughly on par with one another.
*Minato enjoys sporting a kunai in his taijutsu, Itachi leans more towards thrown weapons. So if you count thrown ninja tools, they are close to being on par. If you take that away, Minato has a slight lethality advantage (a blade > a fist, in this case).
*Minato has the better reaction, this is going to be a heavily argued point but even with the Sharingan the best Itachi could hope for is to match Minato's reactions.
*Now the real advantage for Itachi is the Sharingan of course. It puts his speed (in reaction time) close to or on par with Minato. However, it does one better than that, it helps him memorize Minato's style and the longer the battle goes on I'm sure the better Itachi gets in terms of reading him.
*Stamina / Chakra reserve, even if this is healthy Itachi I believe he's always had a low stamina stat. So I'd say while a long battle helps him get an edge with the sharingan it is also a double sided blade in the fact that he will tire out faster than Minato.
I honestly voted Minato because in the few fights we've seen him in, he almost favors up-close fighting than he does anything else. (Yes, I realize he uses ninjutsu primarily in conjunction with being up close.) Itachi is more of a ninjutsu (genjutsu, really) mid to long range fighter, throwing him outside of his usual game zone will throw him off. Minato has the speed, reaction and raw ability to out perform Itachi. However, that Sharingan will likely play a huge part and save Itachi's neck more than once. I believe the combination of a low stamina and sharingan usage will prove to net Minato the win more often than not.
All that said, I could see it ending in a draw as well. A good battle in any regards, nice thread but taijutsu only leaves little to the imagination. Makes for a balanced fight though.