I find this interesting and maybe true:
How is it possible to know the gaming situations since we don't even know what all will be launching next year for either console?
If we go by just what we know about right now, couldn't you apply the same 'worry' to the ps4 in terms of most of the big releases being multiplatform?
The pricing issue will remain and that will likely be the difference. The key is, how big of a difference. If sales remain close enough for MS, they may not feel compelled to lower the price so soon. If there is a bigger gap, then they will feel the pressure.
I know its mentioned that MS might leave Kinect behind, but I think that's probably the least likely thing to happen above all. I'm convinced that they would rather eat the losses of cutting the price to $399 then abandon Kinect at this point.