Predicting hardware sales is a tricky business. Amongst the umpteen figures to consider, user preference is one of the hardest to call. However, UK based firm Screen Digest has planted their flag in the sand, stating that Microsoft’s motion based controller, Kinect will slightly outsell Sony’s answer, the Move by 7.6 million units to 7.3 million units, respectively.

According to GameSpot, Screen Digest’s predictions do not include 2010 sales figures. Normally, this would be a figure to throw by the wayside…if the two products were launched simultaneously, but you’ll remember that Move was out months before Kinect. It’s also noteworth, as Microsoft announced in November that it has moved 2.5 million Kinect units, and was well on pace to deliver 5 million by the end of this year.

Given these numbers, and Microsoft’s statements and additional numbers, moving 2.5 million units per month in the holiday buildup seems completely reasonable. Post holiday shopping will naturally see a decline, so let’s slim this number down to around half a million units per month. Even at this growth rate, Screen Digest’s numbers are a tad low. Meaning – although Screen Digest is lying on the conservative side of the numbers, it’s very likely that we could see Kinect push over 10 million sales in 2011.

Note: Piers hardin-Rolls from Screen Digest commented at Gamasutra clarifying the numbers:

“Our [data] actually refers to new Move and Kinect enabled consoles added during 2011, not installed base, which we forecast to be 11.7 million for Move and 12.1 million for Kinect by end of 2011.”

Adding: “Please note that the Move numbers refer to Move-enabled consoles and not total Move peripheral sales (as a % are bought for multiplayer gaming on single consoles).”

And while Sony may have answered the Nintendo Wii with it’s own motion based control, it’s a case of too-little-too-late. While Sony spent time developing at system that amounts to nothing more than a Wii in HD, Microsoft developed an entirely new product and input method. Coupled with Move software’s dreadful sales, it appears as though Sony has delivered the golden egg.

Screen Digest also noted a few other Sony shortcomings when it comes to all-things-digital. The much hyped and anticipated arrival of 3D televisions has been less than overwhelming, with the firm saying that 3D TV sales will fall flat in 2011. They state that broadcasters are putting too much focus on sporting events and non-recurring programming for consumers to find value in said television.

Also of note: Screen Digest wasn’t any friendlier when it came to streaming gaming services, aka OnLive and Gaikai. The postulate that neither device offer a compelling experience, ultimately providing a poor value proposition.