From the beginning, Windows Vista was envisioned as the next-generation platform that would define the next decade of computing. That goal hasn't changed.
WinFX. A programming model that will replace today's Win32 and .NET Framework APIs, WinFX takes the best features of both of its predecessors and offers a logical evolution to managed code.
Windows Presentation Foundation (codenamed Avalon). WPF is the unified presentation layer in Windows Vista and the foundation for the Aero user interface. It consists of a display engine and the associated WinFX-based code framework developers will use to exploit it.
Aero. The Windows Vista user interface will provide a tiered experience that will vary based on the underlying capabilities of the PC's display hardware. On the high-end, Aero Glass will provide the premium Windows experience, while Aero Express will resemble the graphics capabilities in Windows XP. For compatibility, Microsoft will also include a Windows Classic interface that resembles Windows 2000.
Windows Communication Foundation (codenamed Indigo). Microsoft's next-generation Web services platform provides a simpler way for application and service developers to access logic on disparate systems.