Specifically, some users receive a “generic -50 error” when attempting to connect to the iTunes Store. Some have been successful with simply re-launching the application, while others have been unable to access the iTunes Store altogether.
To check to see if you have gotten the silent update, open iTunes, then go to iTunes > About iTunes… in the menu bar. If the version that scrolls in is iTunes 8.0.1 (11), you should re-download and re-install iTunes 8.0.1.
The current version of iTunes 8.0.1 for Mac OS X now stands at 8.0.1 (12).