Five of the top 6 averaged over 40 last year, although bell with 40.26 and collingwood with 40.89 only just made it. The other strauss, had poor form and only averaged 28.8 - since then he is apparently rested and should play better. The games before the last test were encouraging.
Admittedly some of thee averages were boosted by the west indies series. Aghainst sri lanka
cook 46.33
bell 43.50
vaughan 35.83
collingwood 33.00
pietersen 25.20
Pietersen's decline has been the most disappointing. In the past he has played attackingly and got out. People then criticise him for playing attackingly. Some of the dismissals have been over-attacking but i think that attacking is what he does best so he should carry on with it. Collingwood has also played less well recently and seems to get overly negative at times. However, given the poor state of england's bowling the few overs he can put in are becoming increasingly useful.
There cannot be any serious suggestion that any of the batsmen should be dropped. Then again, there cannot be any serious suggestion that Hoggard should be dropped either, so perhaps that's not terribly important.
But anyway... Pietersen remains by a comfortable distance the only batsman available to England who has the ability to play multiple dimensional innings. Yes, he hasn't done it for a little while, but when you can play knocks like his 142 at Edgbaston in 2006, and score consistently against as menacing an attack as Australia's in 2006\07, you do not get dropped if the selectors are possessed of sanity.
Cook is clearly England's best opener for quite a while (possibly since Boycott) and should be in the team for the next 13 or 14 years at least.
Bell, apart from The Ashes 2005 and to a lesser extent India 2005\06 (where he batted just 4 times outside the opener's slot), has pretty much never failed to score in a Test series. That he has often had "pressure off" runs is not his fault, and it's not like he's totally disappeared when the pump has been on, either. He's performed less well, but frankly so will almost every single batsman in history.
Collingwood's summer 2007 was probably his best Test season of his career.
Vaughan should not be opening but his 2007 was easily his best Test season of his career. Just get him back to three FFS!
Strauss should not be batting three, and probably should not be playing. But surprise surprise, he is.
Ambrose has only played 1 Test, and batted well in the first-innings and received a RUD in the second-.
So really, no changes can be justified here.
Anderson's game in WC2003 against Australia produced figures of 9-66-0. It was in the preceding VB Series in which he turned-out the remarkable 10-12-1.