The remaining half are apparently the owners of a small number of Samsung branded Windows Phone 7 devices. Some of these handsets have a unique issue that prevented the software from getting installed on the phone. Microsoft is working on fixing the problem. In the meantime, the update for Samsung phones has been turned off while users of some models like the Samsung Omnia7 have reported watching their handset turn into a brick, thanks to the problem.
The guys in Redmond have passed along some suggestions to help those having problems with the first update to the OS. Because it is not being done OTA, Microsoft suggests making sure that your PC has enough hard drive space and that your connection to the internet is a solid one. If the Windows Phone 7 in your hand says Samsung on it, that is a different matter that might require you to wait for the software company to come up with a solution to whatever the problem is that prevents your handset from getting upgraded.
source: WindowsPhoneBlog via Engadget