<TreeView ItemsSource="{Binding Nodes}">
            <TreeView.ItemTemplate>
                <HierarchicalDataTemplate DataType="{x:Type local:INode}" ItemsSource="{Binding Nodes}">
                    <TextBlock Margin="2" Text="{Binding Path=Name}" />
                </HierarchicalDataTemplate>
            </TreeView.ItemTemplate>
        </TreeView>

public class MainViewModel : ViewModelBase
    {
        #region Private Fields

        private readonly IDataService _dataService;

        private INode _selectedNode;


        #endregion Private Fields

        #region Public Constructors

        /// <summary>
        /// Отправная точка, главная ViewModel.
        /// </summary>
        public MainViewModel(IDataService dataService)
        {
            Contract.Assert(dataService != null);
            _dataService = dataService;
        }

        #endregion Public Constructors

        #region Public Properties


        public List<INode> Nodes { get; private set; }

        public INode SelectedNode
        {
            get { return _selectedNode; }
            set
            {
                if (_selectedNode != value)
                {
                    _selectedNode = value;
                    RaisePropertyChanged();
                }
            }
        }



    #endregion Public Properties
}

public interface INode
    {
        #region Public Properties

        string Name { get; }

        List<INode> Nodes { get; }

        #endregion Public Properties
    }