Wasn't Mr. Card the go-to-guy/big-idea-guy who came up with the Harriet Miers nomination?
Sure was.
He was even yelling at people when they were critical of her before she even became the pick.
But Card isn't going anywhere.
He has already had one of the longest tenures as chief of staff in history, and its more likely that he'll break the record, Snowe isn't looking to leave and wants to stay.
That said, Card is not overworked, in relation to past chiefs of staff, he actually has a much lighter workload, as President Bush prefers to deal with his cabinet more directly and face to face and meet with them personally as opposed to using the chief of staff to play filter and everyone going through the chief (think the anti-sununu).
Dick Cheney also picks up alot of the workload along with his staff, and Karl Rove is a deputy chief of staff and senior advisor, so alot of the meat and bulk of CofS job is already being taken care of by other people.
Card would also have to deal with opposition if he tried to go to treasury from conservatives, Card isn't a supply sider and is actually more along the lines of a moderate to neo-liberal.