Donovan - Definitely no
Dempsey however could be interesting. I do not see him competing at all with any of our top 3 wingers, but if he were to adapt to a target man striker, which he sometimes does at fulham, he might be a decent complement to rooney. But i think he is the type of player that needs to get on the ball a lot to get settled into the game, which he gets plenty of at fulham. This would be similar to the ruud rooney combo that did not flesh out as good as it looked on paper, so id say no to him as well.