Any good AS Politics will tell you that there are 3 types of responsibility that a Minister has to observe - collective, ministerial and individual. With the formation of a coalition government who'd have thought the first two crisis points would be because of individual issues rather than collective ones (and by two LibDems!).
Chris Huhne, however, will politically survive his marital problems. That is because, unless there is more to come out, there is no law breaking, no hypocrisy and no lies to the public involved. I guess he'll also survive because the government couldn't hack losing a second LibDem Secretary of State in a row within six weeks of taking office. A friend mused that it also because there are few LibDems MPs left whom you actually appoint to the cabinet.
So all-in-all he's pretty safe at the moment, but it will be interesting to see if the mud sticks throughout the rest of his Ministerial and political career.