FYI:  After watching this dimecasts video, I realized that you no longer have to use the Record() Playback() routines, you just have to use the extension method Expect.

So instead of:

var mock = new MockRepostitory();

var foo = mock.StrickMock<IFoo>();

using (mock.Record())

{

     Expect.Call(foo.DoSomething()).Return(something);

}

using (mock.Playback())

{

     var fooB = new FooB(foo);

     bool result = fooB.IsSomething();

     Assert.IsTrue(result);

}

The code to mock is:

var foo = MockRepository.GenerateMock<IFoo>();

foo.Expect(x => x.DoSomething()).Return(something);

var fooB = new FooB(foo);

bool result = fooB.IsSomething();

Assert.IsTrue(result);