Motorola has started the Ice Cream Sandwich ‘soak test’ for a bunch of XOOM owners who had signed up for beta testing the software. The update is being rolled out only for the Wi-Fi edition of the XOOM. If there are no major bugs or issues with the ‘soak test’ build of Ice Cream Sandwich for the XOOM, then Motorola will roll-out the update for the general XOOM owners as well. From the screenshots some XOOM Wi-Fi owners have posted online, it looks like Motorola will not be updating the kernel to 3.0 on the XOOM with the Ice Cream Sandwich update. While this may not affect the general consumers, it does mean that we will not see the l0w-level performance improvements and optimization the new kernel brings. All the changes brought about the new Linux kernel 3.0 can be found here. Even Sony is taking a similar approach on updating its handsets to Ice Cream Sandwich. The company has confirmed that it will not be updating the kernel version of its Xperia handsets, because it thinks that the current kernel version is properly optimized for the hardware of its handsets.
(Source)