Is it absolutely safe to display a WPF window from a WinForms form?

I would like to display a WPF window from a windows forms application (.NET 3.5).

This code seems to work without any problem in a sample project:

public partial class WinFormsForm1 : Form
{
    public WinFormsForm1() {
      InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e) {
      WpfWindow1 w = new WpfWindow1();
      w.Show();
    }
}

The form is started from Main() as a normal Winforms form:

Application.Run(new WinFormsForm1());

This seems to me too easy to be true. Are there any shortcomings in this? Is this safe to do?