Prova questo 
codice:
Public Class Form1
Dim WithEvents tim As New Timer
Dim TheLabel As New Label
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
TheLabel.Location = New Point(20, 20)
TheLabel.Parent = Me
TheLabel.AutoSize = True
TheLabel.Text = "Questo è un testo di prova "
tim.Interval = 100
tim.Enabled = True
End Sub
Private Sub tim_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles tim.Tick
Dim t As String = TheLabel.Text
t = t.Substring(1) & t.Chars(0)
TheLabel.Text = t
End Sub
End Class
TheTruster