Yes, you can purchase and download it from Steam.
Steam should download it automatically, or get it to check for updates.
Skyrim is on PC, PS3 and Xbox360.
Steam's listing for Skyrim doesn't include any Mac systems in its System Requirements. So the answer's probably no, at least for now.
Yes, Skyrim will be out for the PC, 11/11/11 is the release date.
No sorry. Only on PC. The word your looking for is mod by the way.
Skyrim is only on XBox360 , PS3 and PC.
Skyrim DLC for PC is out as of 8/2/2012 in the Steam Store.
Yes. Skyrim is also out for PS3 and PC.
You cannot play the PC version of Skyrim on a X-Box 360.
Mature
There is no way to use your existing Xbox 360 controller on your PC. However, Microsoft have released a PC controller which is a Xbox controller.
You can download Samsung PC Studio 3. Samsung offers "Samsung PC Studio 3" on their website available for download from their website. This is a way to download Samsung PC Studio 3.