Slavery is old yet still with us (and not isolated to "barbaric" cultures, like we tell ourselves).
We treat animals horrifically.
If past (and present) action is any indication, it seems inevitable that we'll abuse AI. The difference being that while the seamstress, farmers and cattle can't stand against our might, AI could. And we'd probably deserve it.
AI itself won't obsolete us. It is my understanding that AI is purely virtual, and can't interact with nature except through agents. For us to be "obsolete", AI needs full production capability to build its own agents, and control the entire production/construction/repair pipeline.
In my view, that's quite a few steps further than simply "AI". An AI with reproductive capability will enslave us before it obsoletes us. And an AI may well decide that human slaves are cheaper (or more useful/versatile) than agents that it can build itself.
Not disputing that it'll happen sometime, BTW - I just don't see this as some great good thing.