I've been running my MendelMax called the Bumblebee II using a Raspberry Pi 512 lately. It runs the printer great once I commented out the visualization display. The one issue I was having is that when it loaded the gcode file, apparently it was still doing some processing to estimate how long it would take to run and the dimensions of the print.
While that is a nice feature to have, there were two HUGE drawbacks to this on a small system like the Pi. The first was it would take a while to load up a gcode file to print, and if it was too large it would run out of memory.
So I dug into pronterface.py tonight and I found the call to do the previsualization when it loads a file. A simple comment out of this line and now my GCode files load instantly into pronterface, and I can print any size file my printer can handle. I need to make a minor change though and display a message that it's read the file and display the filename in the console.