I like the idea of a zodiac and signs for sims, but I think the zodiac should be a new one made of whole cloth, rather than using the Greek Zodiac.
1) the interpretations of each sign are then firmly in Maxis' control, and while there will always be people saying that this or that should have been done differently, it won't be because Maxis got it "wrong"
2) with the calendar being part of Seasons rather than base game, it feels... weird, somehow, to use a calendar based zodiac. I know it was done in previous Sims games, but it still feels weird to me.
3) The Greek Zodiac isn't the only one out there. Rather than pick one real-world zodiac over the others, a fictitious one doesn't play favorites with real-world cultures (and specifically over-reliance on the western world.)