What Direct X for SOW?

[dcal]

Please accept my apology if this has been asked before. Does anyone know what Direct X SOW will be in? 10, 10.1, or 11? I have been slowly piecing my new computer together over the last 6 months in preperation for SOW. The only things I have not gotten are the components at the heart of the rig, namely the CPU, MotherBoard, and Graphics Card(bought dual channel DDR 3 becuase I know for sure I am going with AMD Phenom II or the new Intel Lynnfield). I am probably going to wait until the last part of this year or early next year for the new ATI 5870 and the rest, but prices on the radeon 4800 series are looking very attractive (4890 for less than $200 on New Egg!).

It sure is tough looking at what I have so far and having to wait to buy the main components, but it is going to be very much worth it the first time I push that throttle forward on what promises to be the greatest flight sim ever made. Your thoughts are much appreciated.