In making a vegan version of buffalo wings for my Superbowl party this year, I came across a pretty good butter substitute. It's called Soy Garden (4th product in the link below) and it actually tastes like butter. There's no hydrogenated fats in it. I don't know how it stacks up in the saturated fats department, since that wasn't a factor for me. I gave the tub to my friend to take home, or i'd go check. Stop and Shop carries it (in NY at least), but I would imagine your local health food store would as well.
For the vegan wings I used tofu that I cut in half, drained (and sandwich between cookie sheets and paper towels, with some 28 oz tomato cans on top for at least 1/2 hour) and marinated in Frank's RedHot and then cut up into cubes and threw into the deep fryer (before the chicken wings went in). The sauce was the Soy Garden butter with Frank's Hot Sauce. I also like to throw quirky stuff in my wing sauce and this years' version had fresh basil, dried oregano, evaporated cane juice (i.e. organic sugar), garlic powder and unfiltered apple cider vinegar. I used the same sauce with real butter for the chicken version.