To those saying DJing takes no talent, that's pure ignorance. If you're just playing requests, and fading them into eachother at the end then yeah, you can learn how to do that in minutes. But really DJing is so much more involved and there's no way you can say that a good DJ doesn't have talent.
And Ableton, though sick for producing, remixing, and making mashups, is not the best at actually allowing you to DJ live. It can be good to accompany other software if you're using multiple controllers though.
Traktor is the best DJ software that I know of, and it's as simple or as complicated as you want it to be.