The US is tackling the problem of jointness the right way. Jointness is used to describe operations in conjunction with another (or mulitple other) military arm(s) (such as Air Force coordinating with the Marines).
The US has set up a Joint Qualification System which offers points depending on joint actions each officer has had in the past, but can also gain by attending joint courses and excersises. Enough points result in a Joint Speciality Officer (JSO) designation.
From 2008 officers may not reach flag rank without a JSO.
In a way it’s crazy that interservice rivalry has been allowed to flourish so long and that armed forces have fought as such seperate units. Nowadays with communications being at the point they are there is no excuse for non-jointness in the armed forces.