Probably what it will be. To face court marshal after Odumbo trading him for 5 big cheeze terrorists would make Odumbo look even more stupid. Likely the general in charge has been given a talking to.
Bergdahl deserted his post. That is a statement of fact and is not debatable. What's left to be found is how aggressively he will be prosecuted. My guess is they're waiting for time to pass and they'll eventually drum him out as quietly as possible, after November, which is of course by design. He'll do no time other than what he spent in captivity, which was his choice to begin with. That will be debated between people who deal in facts, and leftists who deal in make believe. No minds will be changed. In the end all that will matter is those who lost their lives and their families will receive little solace, Bergdahl will live his life out with his goofy family, and the world keeps spinning, such as it is.
Actually some former military JAG people have already weighed in on this. The reality is that he was AWOL, and did not Desert. Bergdahl went AWOL before and each time he came back. The military has no proof that he was trying to permanently desert when he was captured by the Taliban; the only case they will be able to prove was that he was Absent WithOut Leave for a period of less than 48 hours before captured. The military punishment for being AWOL is pretty light. Even if they tried him for being AWOL the sentence would be meaningless. Most military officers will think that it is better that they just drum him out over time quietly and not create a PR fuss.