Your code should actually work in 2010 as long as the shape called Rectangle 7 exists.
The main reason the recorder was dropped in PPT was that it produced appalling unreliable code and PowerPoint had become much more complex and many items no longer worked at all.
See if this gets you closer.
Code:
Sub fixCode()
Dim newShp As Shape
On Error Resume Next
ActivePresentation.NotesMaster.Shapes("DATEFOOTER").Delete
Set newShp = ActivePresentation.NotesMaster.Shapes.AddTextbox(msoTextOrientationHorizontal, _
Left:=229.5, _
Top:=690, _
Width:=300, _
Height:=32)
newShp.Name = "DATEFOOTER"
With newShp.TextFrame.TextRange
.ParagraphFormat.Alignment = ppAlignCenter
.Font.Name = "Arial"
.Font.Size = 11
.Font.Color.RGB = RGB(Red:=88, Green:=48, Blue:=151)
.Text = "Page ": .InsertSlideNumber: .InsertAfter Chr(13)
.InsertDateTime ppDateTimedMMMMyyyy: .InsertAfter " ": .InsertDateTime ppDateTimehmmAMPM
End With
End Sub