I'm mixed on the computer DJ, while I do believe it will happen I don't think it will be that wide spread. The computer DJ will probably end up in a lot of bars or small cheap clubs. I believe it would almost act as a sort of high tech jukebox. Great for places with a low budget that only really do Top 40 or more common music.
House, techno, d&b & hip hop clubs will still have DJs where musical talent is required.

Lastly, if it ever comes to the point where an AI robot DJ can CREATE music with as many layers and subtle sounds as humans can in months, but live? Well then, we're screwed. Skynet has gone live and the apocalypse is here.