Comment 1 for bug 385092

That one is a tricky issue, and the "expected" result is not so obvious.
Your proposition means that mouseover events change the selected item in a list, which had never been the case before.
Another solution would be not to change the highlighted item when hovering with the mouse.
There are pros and cons for both of those solutions, but in any case the one we'll pick needs to be carefully thought of.