Motorola XOOM WiFi Android 4.0.4 update leaks with detailed improvements
According to the xda post, this is the official OTA update from IML77 (4.0.3) to IMM76 (4.0.4) for the WiFi only XOOM (codename wingray), although given that Motorola just started up the soak test, we're not sure this is actually the real update. So far, the update does seem to be working pretty well for users. Updating using this file only works with stock recovery, so don't try if you're running ClockworkMod.
Expected improvements in this update include: faster screen rotation, a new setting to choose whether the power button immediately locks the device or not, Microsoft Exchange improvements with additional EAS policies, better phone number recognition, camera and image quality improvements, and improved stability.
If you're interested, you can grab the zip from the xda forum post here.
source: Droid Life