Are there any tools that allow me to view the rich meta data that .NET assemblies have? Is there a OLEVIEW equivalent for .NET?
Currently, the best one that I know of is the Reflector for .NET by Lutz Roeder. You can find it here along with other useful tools.
Reflector for .NET
You can also use the Windows Class Viewer (wincv.exe) and ILDASM (ildasm), both of which come with the .NET framework.