SDL, I think you are making the hover show up using CSS correct? If so, the CSS equivelent to hover for keyboard users, is :focus. The click may work depending how it is used. (As a keyboard user, I can test)
:focus does not work correctly (at all) in IE6 or 7, which may still be popular with users of older Windows screen readers.
:focus does not work on elements without a natural focus ability (which would be anchors and form controls). So, not tr's.
OP: if this flourish isn't really adding anything, don't make it more complicated for everyone else. Sometimes it's ok to just have something for mouse-users only, because it's an enhancement (got a mouse? yay you get to do something cool/weird/stupid/cute) and not essential.