I suspect that Manning will be convicted and spend several years in prison. He seems to be a sympathetic pathetic character to me. If, as what I read suggests, he broke the promises he made to get a clearance, broke the law, and his action damaged US interests and endangered lives, then serious punishment is appropriate.
US claims against Assange seem less clear. I don't know what US law he violated and I don't know how the US can claim jurisdiction. I found reference to a rumor of an indictment at wikipedia, but I'm not sure that the US has charged him. The Swedish charges seem plausible and unrelated.
I have more sympathy for Manning than Assange, perhaps because the case against him looks clearer and more serious.