Looks like Research In Motion is trying to pull all BlackBerry handsets up to the same OS level and have released the 4.5.0.163 OS to several handsets reports Crackberry.

The 4.5.0.163 OS has now been pushed out from Vodafone UK to the BlackBerry 8100, 8110, and 8700 and from MobiStar for the BlackBerry 8320, 8800 and the BlackBerry 8820.

All these 4.5.0.163 OS releases are official, however may not be for your particular carrier, so if you intend to upgrade follow the guides which can be found by hitting up the link.