Speculating...
It is possible that there may be some security flaw which dictates this M$ move....but I doubt it.

Considering 4 factors...

1- the recent "mass-killing" of so many M$ jobs and the necessary leaner business/ corp. model they are trying to achieve...skype for legacy is bound to be on the chopping block...not enough reason to expend resources on it I'm sure.

2- Since M$ takeover of Skype...enough time has now elapsed that fewer condemning eyes are watching and fewer voices will be in outcry compared to when they 1st grabbed Skype....and their predetermined method of tactics is now to carry out Plan B...followed by goodness-knows-what PlanC ...etc.

3- Not surprised about Mac's either...which leads in part back to point #2...
Obviously ANY device not towing the M$ OS party line...Especially M$ devices and operating systems that are more recent (win phone 7 for example isn't immune ...so it naturally is extrapolated that our devices don't have a "fart in a windstorm's chance" of keeping it either) ...will be dropped.

4- Perfect business model to help push people into the new line of M$ devices who specifically need Skype.



So it seems so far to be those affected are:

-Devices that are other than M$ devices.

-especially Devices Other than M$ devices that run older OS's let alone M$ OS's that have run the time-expired course of M$ corporate responsibilities to said parent device company.

- I would imagine that ergo...
the n8x0 line will also be affected and possibly non-working

I stand clapping...commend and applaud the ruthless efficiency of Microsoft's "brush-fire" (very appropriate term) tactics of driving the digital animals out of the mobile forest ahead of the fire.

BUT.
There may still be hope for us!
Possibly running a linux distro on your device may circumvent this "Skypocalypse" if even one applicable distro is immune.

This is especially fortuitous for those who will be using the neo900.