No, the Iron Mike cannot be set up to throw pitches at random speeds. The balls would be anywhere from way too high in the strike zone to bouncing in front of the plate if speeds were random.
There is only one pitching machine that I know of that is capable of throwing random speeds and also adjusting the vertical and/or horizontal pitching machine head angle to compensate for a "random" different pitch speed/type. It is the eHack Attack baseball only pitching machine and it costs about $9,000 for just the machine. An automatic ball feeder for that machine costs an additional $549 or $1,799, depending on the ball capacity that you need. You can convert it into a softball throwing machine for an additional $900, as well.