After installing and starting up Toad for MySQL Beta 3.0 I get:

Couldn't load assembly ToadCore.dll

Details:

Exception : Quest.Toad.Exceptions.BaseException
Message : Couldn't load assembly ToadCore.dll
Stack Trace :
at Quest.Toad.Util.AssemblyLoader.LoadAssemblies(IEnumerable filenames)
at Quest.Toad.Util.AssemblyLoader.Load(String[] directories)
at Quest.Toad.Util.AssemblyLoader.Load(String directory)
at Quest.Toad.StartupForm.LoadPlugins()
at Quest.Toad.StartupForm.Main(String[] args)

Inner Exception : System.Reflection.ReflectionTypeLoadException
Message : Unable to load one or more of the requested
types. Retrieve the LoaderExceptions property for more information.
Stack Trace :
at System.Reflection.Module.GetTypesInternal(StackCrawlMark& stackMark)
at System.Reflection.Assembly.GetTypes()
at Quest.Toad.Util.AssemblyLoader.LoadAssemblies(IEnumerable filenames)