Witness feminist mom-of-the-year, Andrea Yates. Any point beyond conception is a slippery slope.
Yes, if a "fetus" isn't a live human at conception, at what point does "it" magically become one? Mrs. Yates and her feminist defenders illustrate to me how America as a nation has lost much of it's reverence for human life since Roe v Wade. I don't know what worries me more, Mrs. Yates's apparent lack of remorse or the women who see her as the primary victim in the tragedy.
I think your term "slippery slope" is an apt description of what this nation is experiencing at least partially as a result of Roe v Wade. First it was abortion, then it was the abominable "partial birth" abortion, and now assisted suicide has been approved by voters in one state. How long will it be until full-blown infanticide gets the official OK? (Actually I believe partial birth abortion is full-blown infanticide, but I can't think of any other term to differentiate it from the killing of babies wholly outside the womb)