I know this story already made the rounds last week, and lots of people have had their say at this point. The community has arrived at pretty much the same opinion and I probably wouldn't feel the need to join in except that I have some technical background that might help put some of this in context.
Last week, Ubisoft was showing off Assassin's Creed Unity, where you can customize your own assassin for use in multiplayer. However, you can't play as a woman, because making alternate female models and animations would double the production costs. Then a former Assassin's Creed developer (now departed from the company) said that making a female character should only take "a day or two's work". So who is right and who is lying?
As it happens, I have a little experience with this kind of thing. About eight years ago I worked on software that had customizable male and female avatars, and before that I actually made some of the models myself. So I have experience both with the art and programming side of this. However, note that my knowledge was a little out-of-date even then. I wasn't working on high-tech bump-mapped and motion-capped models like the folks at Ubi. But I did make 3D people and I did make animations for them and I did write the code that drives them. So my knowledge is broad, but out of date. And in my quasi-expert opinion: Both of these claims are basically true.
See, when it comes to animating something as complex as a human figure, the real work is in the refining. Yes, you can slam out art assets pretty quickly, especially when you've got a huge budget and a lot of dedicated artists. The problem is that the process doesn't end when the artist hits "Save". They make the art, then you put the art together, then you do lots of playtesting so see how it all looks and feels, then you compile a list of concerns and send it back to the artists. Repeat until the game is polished. And no matter how much money you throw at the problem, you can't do much to speed that process up. Iteration takes time, and iteration is how you achieve greatness. So while it's possible to slap a couple of simple female characters in there in the space of a few days, it would take more than a couple of days to make them look as good as the males.
A big part of the problem is that males and females are proportioned differently. Given a man and a woman of the same height, the man will have more of his height in his torso and the woman will have more of her height in her legs. The man will also have larger hands and a slightly longer reach. Now, if this was just a game where you run around and shoot people then those slight differences might not matter. In Mass Effect, Female Shepard used the same (male) animations as Male Shepard and they (mostly) got away with it. But Assassin's Creed is a game where you're constantly interacting with the environment and other figures, and doing so in a non-cartoony world where visual fidelity is important.