I'm just poking around the new framework, dealing with corflags and CLR Header versions (more on that later), but what I found is the following.
Do a dir *.dll /o:-s in the framework directory. You get this on .NET FX 4.0 beta 2 box:
[c:\windows\microsoft.net\framework64\v4.0.21006]dir *.dll /o:-s
Volume in drive C is 7 Serial number is 1ED5:8CA5
Directory of C:\Windows\Microsoft.NET\Framework64\v4.0.21006\*.dll
7.10.2009 3:44 9.833.784 clr.dll
7.10.2009 2:44 6.072.664 System.ServiceModel.dll
7.10.2009 2:44 5.251.928 System.Windows.Forms.dll
7.10.2009 6:04 5.088.584 System.Web.dll
7.10.2009 5:31 5.086.024 System.Design.dll
7.10.2009 3:44 4.927.808 mscorlib.dll
7.10.2009 3:44 3.529.608 Microsoft.VB.Activities.Compiler.dll
7.10.2009 2:44 3.501.376 System.dll
7.10.2009 2:44 3.335.000 System.Data.Entity.dll
7.10.2009 3:44 3.244.360 System.Data.dll
7.10.2009 2:44 2.145.096 System.XML.dll
7.10.2009 5:31 1.784.664 System.Web.Extensions.dll
7.10.2009 2:44 1.711.488 System.Windows.Forms.DataVis.dll
7.10.2009 5:31 1.697.128 System.Web.DataVis.dll
7.10.2009 5:31 1.578.352 System.Workflow.ComponentModel.dll
7.10.2009 3:44 1.540.928 clrjit.dll
7.10.2009 3:44 1.511.752 mscordacwks.dll
7.10.2009 3:44 1.454.400 mscordbi.dll
7.10.2009 2:44 1.339.248 System.Activities.Presentation.dll
7.10.2009 5:31 1.277.776 Microsoft.Build.dll
7.10.2009 2:44 1.257.800 System.Core.dll
7.10.2009 2:44 1.178.448 System.Activities.dll
7.10.2009 5:31 1.071.464 System.Workflow.Activities.dll
7.10.2009 5:31 1.041.256 Microsoft.Build.Tasks.v4.0.dll
7.10.2009 2:44 1.026.920 System.Runtime.Serialization.dll
Funny how many engineer dollars are/were spent on middle tier technologies I love.
Proof: System.ServiceModel.dll is bigger then System.dll, System.Windows.Forms.dll, mscorlib.dll, and System.Data.dll.
We only bow to clr.dll, a new .NET 4.0 Common Language Runtime implementation.