Distributions with built-in proprietary drivers
 

Austrumi and Mandriva One 2010.2 have this for example. You can use them as LiveOS or install but they already have proprietary drivers without need to download or check if compatible etc. Are there any other distros with included proprietary driver support?

Yeah many. Why don't you check on distrowatch.com? Also, each distro has its own documentation/wiki that describes how to install the driver and on which hardware it works. It's a question of choosing your own flavour, no more.