From what people keep saying about AVB's preferences all the time, I get the impression that he wants players who can run quickly and far, but it doesn't matter much what they actually do with a football. I'm sure this is not entirely accurate. If that is the case, I also fail to see why he signed Dempsey, for example. He is not a quick player, nor is Sigurdsson, although he was perhaps on his way here before AVB was?
I think all players we signed this summer were players AVB wanted, regardless of if we were after them before he officially signed or not. All the following obviously just my impression based on what I've seen so far.
He wants more dynamic and athletic players in general, but he also wants players who are good on the ball and he wants those players all over the pitch. Starting at the back. Harry signed Bassong who was quite poor on the ball even for a defender and looked happy with Hutton who was not only all round terrible, but also poor on the ball. He also seemed very satisfied with Dawson, who can play some good long balls, but his close control is far from good. AVB brought in Vertonghen who is excellent on the ball, kept Caulker (also very good on the ball) around and put him ahead of Daws in the pecking order and brought in a goalie who is very good with the ball at his feet.
Further forward he brought in Dembele, we all know what he's capable of with the ball at his feet and of course Adebayor. The only two signings that are being brought into question generally are Dempsey and Sig. Both are at least average to good on the ball (for their position), and they also work really hard for the team. He let Kranjcar and VdV go, both players who ranged from good to great on the ball, but who struggled with fitness issues and weren't exactly reliable defensively.
I think he would have preferred someone even better than Dempsey, as was seen by us bringing him in very late in the window. Moutinho? Willian? I don't know, but I'm guessing he wanted someone who has a bit of everything, but even more skills on the ball. Dempsey came in and is a fairly versatile player who I still think will do a solid job for us.
As far as I can see there is a consistency here, and it's not only players that can run quickly and far without being good on the ball. Again I want to compare us to United where Ferguson often has relied on complete players who can do everything, but also are good on the ball to put together a team that works as a unit, not just a team of individuals. But comparisons could also be made to some other very successful sides.