Either GM is simply biding his time and has plans for a major coup or he is terribly delusional and thinks this team as constructed will somehow gel and mature. If you really believe the latter then you don't go calling up young defensemen like a revolving door. This is normally done due to injury, we have no significant defenseman injuries. I think it is the former.
I don't think GM is a SC winning GM but I also don't think he is an idiot. He has always had a vision, albeit not always correct in its application. 07-09 was his vision of the Caps as the team of the future and he wanted to hoard his nuts. That vision has clearly changed since then, so I have to believe that he will make a move. If he does not, then he truly is an idiot.