No he's not in the same league as Thompson, Lillee or Steyn. Its just that England haven't played him well, particularly the tail who got scared.
We stick with Cook. Theres no better opening batsman around and look at the runs he has got in test cricket and he's still only 28. Think Giles will replace Flower soon. Natural progression. Anderson and Swann maybe coming to the end of their careers. You only have so many years bowling in you and Anderson has been playing international cricket for over 10 years. Steyn is only a year younger but he hasn't played as much and started his international career a little later. He played for Warwickshire in 2007 and it wasn;t until 2008 he really brole through.