I already have an application built in asp.net 3.5 and now I want to migrate to windows workflow for business logic. I liked wf 4 but the point is can I use it with my asp.net 3.5 app or am I stuck with wf 3.5 ??
You can't use in in the same process but there is nothing preventing you from using a Workflow Service hosted in a .NET 4 AppDomain.