System.ServiceModel reference is gone after upgrade to vs2010?

I know VS2010 changed the versioning of compiler, more exactly it’s within .NET FX 4.0, but still I want to complain it, why dont you ask or just tell me what’s wrong when I convert solution created from earlier version

 

say I have a WCF solution, I created by vs08 and then the target version is 2.0, then I added some dependencies which target version is 3.5 or 4.0, it works under NET FX3.5, and now I even cannot compile it.

 

how hard to add a function: do you want to upgrade you project target framework from 2.0 to compatible version (3.5/4.0/Apply for all projects)