Apple's OS X 10.4.6 update was released yesterday, and some of the upgrades include new support for Nikon D200 .NEF and Canon 30D .CR2 RAW files, as well as a fix for the EXIF bug for exported TIFF files from Aperture.
In addition, with 10.4.6, Aperture 1.0.1 is now much more responsive. For example, just viewing heavily adjusted 8 MP images on my iMac G5 2.0 through Aperture's loupe was quite a laggy process. Although some of the lag is still there in 10.4.6, it is greatly reduced compared to 10.4.5.
This is a nice improvement for Aperture that will tide us over until the full Aperture 1.1 update arrives this month.