Yes, you can easily upgrade as there are no differences in the method names, property names and so on which could cause a problem in the code itself. However there are some issues to be aware of as explained below.

We have found that in some cases .NET does become very particular about the specific component an application is compiled with. Of course this is by design and is meant to be a useful feature of .NET so that different versions of components can co-exist. In these cases, we have found that it can become necessary to re-compile an application with the new version of a component. Another gotcha is to make absolutely sure the old .NET dll file is completely removed when a new one is being used. Windows has a habit of latching on to the version it started with unless it is physically removed.