Some users are already able to download iOS 4.2. Still, others are getting the "4.1 is the current version" message. Either way, it's worth checking right now. Keep trying, friends, it's coming soon, and we've been waiting for it sever since the initial announcement at Apple's September 1st event, users have looked forward to the update which is promised enhance the usability of the iPad by adding multitasking and printing to the device, the first of which was already possible on the iPhone with iOS4.
While iPad 4.2 was the version we were personally more excited for, mainly because the key functions were already available on the iPhone. We are definitely interested in seeing what iPhone 4.2 brings to the table. Of course the time is now, and we are currently installing it on our systems.
Simply launch iTunes 10.1 (which you should already have if you allowed the update) and hit "Check for Update." You will be notified that 4.2 is available and you can now download the new OS.
Again, make sure to back up your system, and jailbreakers may want to hold off until further notice.
Here's some more info on iOS 4.2 that we've posted in the past: