Sorry if this is a stupid question, a friend has the samsung moment and wanted the software update like we have.is it the same and can he update to the 2.1 from the 1.5?
No. Operating system software is specific to a particular hardware device. Think of the o/s as software that links applications to the binary code that the hardware understands. So while an application's code can be the same for every device/system, they depend on the operating system to "translate" the code into something the hardware can understand and execute.
Your friend will have to wait for the 2.1 Operating system to be "ported" to the Samsung device.