Taking a look at NLog, it's unclear what version works with VS2010. It says that NLog 1.0 Refresh works with VS2010 beta but nothing else is indicated. There's an NLog 2.0 that is pre-beta that I'd rather not use if I didn't have to but it clearly does work with VS2010.
So I'm wondering if I'm able to use 1.0 Refresh or do I need to go with 2.0 Preview 2?
Both NLog 1.0 and 2.0 work with Visual Studio 2010. In case of 1.0 you need to use a build for .NET 2.0 (which unfortunately requires your app to be compiled against .NET Framework 4 Extended Profile), NLog 2.0 does not have this limitation and allows client profile apps as well.
For new projects I would recommend NLog 2.0. It is reasonably stable at this point and is passing all unit tests at this point.