Are there any design patterns used in the .NET Framework?

Question

I would like to know: are any GoF design patterns are used in the .NET Framework?

BOUNTY:

I have seen the MSDN link below in an answer. Are

Answer 1

Here's an article that discusses this very topic:

Discover the Design Patterns You're Already Using in the .NET Framework

And now the MVC pattern can be added with ASP.NET MVC. :)

EDIT: Since your edit / request for more info:

Here's an article that lists several patterns and where they are used in the framework.
Structural Design Patterns and .NET Framework 2.0

The Providers in .NET are all the Provider model pattern:
ASP.NET 2.0 Provider Model: Introduction to the Provider Model

The provider patterns in .NET also use the Strategy Pattern.

The factory pattern is used in several places and here's a sample where it's used in ASP.NET.
Exploring the Factory Design Pattern

Here's a webcast on DP's in .NET:
MSDN Webcast: Design Patterns in .NET

I haven't watched it so I am not sure how much it goes into how they are used in the Framework...

As already mentioned in a comment, the GoF patterns are likely all in use in the .NET framework. Where is not exactly the easiest to answer as the framework is massive and unless MS publishes as such listed in some of the examples given it is not always obvious. The more familiar one is with a pattern the more likely you would notice a framework class that was employing it.

Hopefully the extra links I have added help you.

Additionally, dofactory has a for sale kit ($79-99) that is about teaching how to use/implement GoF patterns in .NET BUT they do list on the reading they will also explain where MS uses them in the Framework.