If we play the way Portugal play we'll be playing 4-3-3. Now as far as I'm concerned, Sheva is not leaving the club and from what I have saw from him he cannot play as a lone striker, Anelka also likes to play off someone, so something has gotta give. We either sign another striker or play 4-4-2 to suit both Anelka and Sheva.
We'll just have to wait and see who he brings in before we see whos playing where. If Deco arrives which has been mentioned, he'll be the creative player we've apparently lacked in recent years. If he comes he will play and we will almost certainly play 4-3-3 imo.
That leaves 2 positions in midfield between Lamps, Ballack, Essien, Maka and Mikel. Obviously we'll need a holding player which leaves Lamps and Ballack. Tough choice.