Maxwell hasn't done anything to prove that he would be a good solution in RF. Not in spring training this year, not in AAA last year. Bernadina had a huge year in 2008 at AA and AAA, plus he was starting to show some promise in his most recent (albeit brief) MLB at-bats. He has refined his swing twice in the past two years, shortening it in order to become a better contact hitter and while I think he may eventually be a good option, let him start the year at AAA and work himself back into a groove
I don't see Morse as an everyday player and Willie Harris is probably the best available option at the moment, but Morse has a good bat and can hit lefties. Harris has good defense and can be serviceable against righties. A platoon of the two does not sound like a bad idea for now. It is all good to let the young guys try to battle their way onto the team, but if none of them show up I would be greatly disappointed if the RF situation stays as it is for the entire season.