Apple just released "Digital Camera Raw Compatibility Update 3.1" adding RAW support to iPhoto and Aperture with the Following cameras

This update extends RAW image compatibility for Aperture 3 and iPhoto ’09 for the following cameras:

Hasselblad H3DII-50
Leica M9
Leica X1
Olympus E-P1
Olympus E-P2
Panasonic Lumix DMC-GF1
Pentax K-7
Pentax K-x
Sony Alpha DSLR-A500
Sony Alpha DSLR-A550
Sony Alpha DSLR-A850

Besides this update Apple recently also released an update to Aperture 3 which is supposed to fix the slideshow issues.

This update addresses an issue affecting the playback of video clips used in Aperture 3 slideshows on Snow Leopard.

The update is recommended for all users of Aperture 3.