About Windows Installer, the .NET Framework, and Visual Studio.
As a photography enthusiast and the son of a professional photographer (SLR, or "single lens reflex"), I am excited to read that Longhorn will support raw image formats from several manufacturers of digital cameras and digital SLRs.
Raw images are pre-pixilated dumps from the image sensor - a CCD - that are comparable to film. Keeping raw images as master copies allow you to produce anything of equal or lesser quality. While most high-resolution JPEGs are suitable for most enthusiasts and even some professional uses, the raw image format - a manufacturer proprietary format, unless Adobe succeeds in getting manufacturers to adopt the Digital Negative Specification - provide all the data about the picture to make lower-quality copies.
Till now, Windows required that you imported and converted these in order to display them in Windows without special software like Adobe Photoshop CS2.
A thumbnail shell extension is also expected to ship before Longhorn for down-level platforms like Windows XP.