I updated Webkit yesterday on OSX 10.6.8 without any additional patches. I cannot enter any url or search string. If I try, no letter will appear like the keyboard was completly disabled. It works of course in any other app and Finder. I also updated today, but the bug still exists.
Nightlies will no longer work with Safari 5.0.x. Please update to Safari 5.1. *** This bug has been marked as a duplicate of bug 68542 ***