Sony will never upgrade the Xplay to ICS, JB or KitKat simply because the Xplay is a gaming device and newer versions of Android are too "heavy" to keep the same gaming performance as in GB, but the Xplay's hardware can actually run ICS and JB.
And personally I'm agreed with them, if someone wants ICS or JB in his Xplay just use a custom ROM but gaming will never be the same as in GB, guaranteed.
Try playing games like GTA III on a GB ROM and then on a ICS ROM, you'll notice MUCH difference (ICS will lag a lot).
Since the Xplay is a gaming device, there's no point on upgrading it to newer versions of Android if gaming performance will be compromised, that's it.
Anyway I really appreciate dev's work on the Xplay and I'm glad to see that this phone isn't dead yet.
P.S. sorry for my bad english, hope you understand