The key perhaps to England going a little farther in the WC lays in the Central midfielders role.
I'm putting this up for debate, many things can change how Capello plays his center mids, like the strikers and wide players.
Capello has his reasons for Heskey it allows the team to be able to play without a defensive midfielder a player thats sole job to only cover in front of defense that we do not have anyway.
If both center mids have ball playing abilities are strong tacklers and can cover lots of ground Heskey becomes a valid player as the middle third front to back under Capello pressure play looks to be around 30 yards beating players one on one becomes extremely hard even for top players.
Having the extra ball player in the middle pairing makes it easier to find openings faster and move control onto the front third of midfield and hold for quick release into a more decisive attack. Heskey if fit gives Capello this option
If Capello puts one player with defensive responsibilities and one offensive in the middle it squashes the middle 50% creatively lessens the chance of players through passes and imbalances how the team can quickly get the ball to different parts of the front third. The team may end hoofing the ball up front a little to often losing to much control for the team to set up and defend.
Both Barry and Lampard can, I feel they can be turned by the best players
Carrick can easily play there when it top form and confident wonder when that will happen.
Gerrard if committed could be excellent under past mangers he could not Capello may have to later on, although I think he is of great value to the side playing left midfield.
Milner has the energy but not the experience and passing ability in that tight position yet. Then again Nobby Stiles and Alan ball were not well known before Alf Ramsey called them up for the 66 England team.