Adobe has released Photoshop Camera Raw 5.4 as a free download from Adobe Labs.
 
Camera Raw 5.4 extends raw file support to an additional 26 camera and camera back models including the Canon EOS 500D (EOS Rebel T1i), Nikon D5000, Olympus E-620, plus 18 Hasselblad models.
 
This is a ‘candidate release’, meaning Adobe would like real-world testing and feedback from its customers before rolling the full release out in all future software. Feedback can be provided on the Adobe User to User forum
 
 
List of additional supported cameras and camera backs in Camera Raw 5.4:

Canon EOS 500D (EOS Rebel T1i)
Nikon D5000
Olympus E-620
Epson R-D1x
Kodak EasyShare Z980
Olympus E-450
Panasonic Lumix GH1
Sigma DP2
Hasselblad CF-22, CF-22MS, CF-39, CF-39MS, CFH-22, CFH-39, CFV, 503CWD, H2D-22, H2D-39, H3D-22, H3D-31, H3D-39, H3DII-22, H3DII-31, H3DII-39, H3DII-39MS, H3DII-50