You have one thing right: if there is no charge on the original accusations, people are going to start raising hell about it, starting with Alan Dershowitz and some other lawyers.
MSNBC said he's going to have a press conference to tell us "where his investigation stands." Well, he's had two years; IMO, a lot of people are going to think that's enough.
It seems he has nothing on the original charge. Probably hasn't for a long time, and the reason this has been dragging on is because he's been stalling, fishing, waiting for someone to trip up after the fact. Hence- the perjury charge on Libby. He's been waiting for someone to incriminate themselves.