1. Load http://www.squarefree.com/start/ 2. Press Ctrl+1 to focus the Google Search textbox. 3. Press Ctrl+A to go to Asa's blog. Result: Nothing happens. Expected: Go to Asa's blog. Note that some shortcuts, such as Ctrl+S, continue to work. So I guess only the Ctrl+letter shortcuts that have "emacs-like keybindings" (e.g. Ctrl+A for "beginning of line") are overridden. I don't know whether WebKit's behavior is intentional, but it's the opposite of Firefox's behavior and it keeps confusing me.
Looks like this worked in Safari, was broken in Safari 3 beta, and works again in release. And we have a test fast/forms/access-key.html that checks for this, so I'm closing as FIXED. Note that an opposite behavior has been requested, as well: bug 7466.
This bug has caused me dataloss (I was in a form field, I pressed ctrl+e to go to the end of the line, and it navigated away from the page). I had to look at the page source to work out what Ctrl+E was supposed to do, since it didn't highlight a menu like Mac apps normally do when I hit an accelerator.
Or rather, the fix for this bug has caused me dataloss.