You know, even if he doesn't appoint Romney to anything, this is a smart move. Meet with people who opposed you, tell them of your plans, etc.. It'll help him rally more support in Congress and among people if he's got more "respectable" types like Romney not carping at him.
Also, it is noteworthy that despite the warnings that he'd be "no better than Hillary", his meetings with people like Cruz and Romney suggest he's going to be closer to a traditional Republican. A lot of folks obviously don't like that, but it still isn't Hillary.