We really should try the 3-5-2 Juve is playing.
I think Vermaelen and Koscielny are really good one v one, and they have the speed to not mind too much being dragged towards the flanks a bit. Mertesacker with his reading of the game and calm between those two chickens would be a bonus as well. Per is not too good with the ball at feet, but then again both Vermaelen and Kos are excellent passers from deep.
We look a bit short in midfield, pun intended, when it comes to a mobile ball winner. We could well use a player like Vidal, but all of Cazorla, Wilshere and Arteta are intelligent footballers, and I think they could make it work quite well anyway defensively. Offensively all three of them are excellent passers and both Cazorla and Jack possess the needed creativity to either drive through midfield with the ball at feet, or release the ball to one of the wide players.
Lichtsteiner and Asamoah are both good players, but for my money Sagna and Gibbs are both comfortably better than both of them. They both have good engines, decent feet and are good at getting into good crossing positions. Sagna is already a very good crosser and there is no reason why Gibbs wouldn't improve his hit rate if there is an extra player in the box.
For our forwards we should of course try to have a target man and a runner in tandem. Vucinic performs the target role for Juve and Quagliarella is always ready to run in behind the defence. Two good out ball options.
For us we have to play Giroud with Walcott, or Podolski with Gervinho. They would roughly offer the same qualities. The flip side to this is that it would get Walcott his coveted spot up front, Podolski closer to goal, and Gervinho would never lead our line by himself.
For me the 3-5-2 is also a very flexible system. When you are under the kosh, which you always are for periods of a game, it is easy to make the switch to a 5-3-2 without any major changes. It would also, in theory at least, solidify us through the middle during those periods of the game when we are under pressure.
Santos is obviously not too well suited to this formation, but all of Jenkinson, Coquelin and Yennaris look to have the raw materials to be able to cope in that wing back position IMO.