You can use the MBP as a second screen using Screen Recycler:
but as Fortuny said, the MPB cannot be used as the primary screen for the mini. If you can get the mini set up and configured using a standard monitor temporarily, though, you could then control and run the mini "headless" from the MBP by using the screen sharing built into Mac OS X 10.5 and later, VNC, LogMeIn, or any of the other remote control solutions.
Message was edited by: Dave Sawyer
No as well.
Only the 2009 and 2010 27" iMacs and the 2011 ThunderBolt iMacs (21.5" and 27") have the ability to be used as an external display.