Agree that Wayne Palmer should come back though--we need to at least know what the hell happened to him!
The show has made it it's business to quickly forget about deposed Presidents. Keeler went down onboard during season four, and although a Fox mandate forced the writers to have him survive the crash, he's never seen or heard again and Logan is shown jovially serving out his term in Day Five.
That actually makes me wonder if Palmer would have otherwise died, but Fox didn't allow them to kill a sitting President, so they just put him in a coma like Keeler. For the same thing happens in Redemption--no mention of Palmer and Daniels is shown to be (less than comfortably) serving out his term!