It features many improvements and cool upgrades that go beyond what many much more expensive machines have.
New features:
- Filament sensor
- Power Panic
- RPM sensing fans and Noctua
- Ambient thermistor and P.I.N.D.A 2 with thermistor
- EINSY RAMBo motherboard
- Trinamic2130 drivers with layer shift detection, faster and silent printing
- New Y axis
- Bondtech extruder
- Magnetic MK52 Heatbed
- Powder coated PEI spring steel print sheet
- Ready for OctoPrint
MK3 presentation video:
MK3 release post with all the details:
http://www.prusaprinters.org/original-prusa-i3-mk3-bloody-smart/