This macro should do what you want:
Sub Autofill2()
Dim myR As Range
Set myR = Cells(Rows.Count, 1).End(xlUp).Offset(-1, 0).Resize(2, 1)
On Error Resume Next
myR.AutoFill Destination:=Range _
(myR, myR.Offset(0, 1).End(xlDown).Offset(0, -1))
End Sub
Alternatively:
Sub FillDown()
Range("A1").Select
Selection.End(xlDown).Select
Range(Selection, Selection.End(xlDown)).Select
Selection.FillDown
End Sub
