Ali, I very much doubt Emerson can play on the left. Zambrotta can push up the left flank, but then still Emerson has to play on the left a lot. It's a good plan to use three if DP/Trez/Mutu/Zlatan, because it would be stupid to bench two of them. King Ale's formation is exactly what Capello will use.
The 4-4-2 with two defensive midfielders in the centre is the most standard formation thinkable, but it's also the most stable one. The only problem is Nedved - I would much rather have DP or Mutu play then him. But neither can play on the left wing in a 4-4-2, so with our current players there really isn't an ideal formation.