Fritzing is an open-source initiative that allows you to virtually design electronic circuits on a breadboard (although you could design circuits that aren't on a breadboard). This could save a lot of hours working on a breadboard if you have this amazing software at hand. In this new version of Fritzing a high-level summary of changes are:

• New basic parts: resonator, tantalum caps, multilayer caps, zener diode, schottky diode;
• New microcontroller parts: Wiring (incl. Mini and USB Adapter), Parallax Propeller, Parallax Basic Stamps;
• SMD footprint support (though still single-sided);
• Import of gEDA footprints (through parts editor, plus 1,000 converted footprints available in parts/svg/contrib/pcb);
• Speed-ups in breadboard dragging and inspector;
• Visual distinction of plurals in parts bin;
• Layers palette;
• Mouse wheel can be set to either scroll or zoom.

But if you're interested in the detailed changes, take a look at the individual code changes clicking here.