The list of supported cameras include Nikon's 1 J1, 1 V1, Coolpix P7100; Olympus' Pen E-PL1s, PEN E-PL3, PEN E-PM1 interchangeable lens cameras; Sony's Alpha Nex-5N, Alpha SLT-A65, and the highly anticipated Alpha SLT-A77; Panasonic's Lumix DMC-FZ150; and Canon's point-and-shoot PowerShot S100. You can find a full list of supported digital camera raw formats on the Apple site.
You can download the 7.2 MB update, version 3.9, from Apple's support site or via Software Update. For those running Snow Leopard, the update requires Mac OS X 10.6.8; Lion users will need Mac OS X 10.7.2 or later.