Is there a way to disable "Top Hits" in the Safari 6 address bar?
The Top Hits section uses the top two sites from your history, so if there are certain sites you don't want showing up in Top Hits, just press option-command-2, and delete the offending sites. (I don't know how to remove it though.)

Edit:

As noted in the comments below, the keyboard shortcut to access History is now Command-Y.