I came across a story about a lawsuit seeking access to emails of Nevada Governor Jim Gibbons [The 698 Update].  The Reno-Gazette Journal sought emails during a specific time-frame with certain individuals.  The lower court ordered production of the emails or an explanation to the newspaper within a certain time-frame.  The appeals court reversed, reviewed the emails in camera, and found that 98 of 104 emails were properly withheld:

Although Carson City Circuit Judge Todd Russell called for the release of six of the 104 emails requested, (all 104 were reviewed by a court master), Russell also contended that the rest of the emails were "personal, of a non-public 'transitory nature' or privileged," holding that most of the mail was confidential under Nevada law.

I haven't seen a copy of the decision, and it's possible there will be an appeal.  It's tough to know what to make of it.  This does remind me that in January, a New Jersey appeals court squashed a similar lawsuit seeking access to the emails of Governor Jon Corzine.  [Death By Email]  The Corzine email case differed from the Gibbons one in that in New Jersey, the court didn't even order in camera inspection.  It ruled that the emails were covered under executive privilege, and the person seeking the messages must present a "focused demonstration of need."  The court ruled that the showing in that case was insufficient:  "Wilson's request for access is based on a general suspicioun that something may be amiss.  His ill-defined and speculative claim must be balanced against the Governor's interest in protecting the confidentiality of information received from a wide range of correspondents."  Access a copy of the decision here [pdf].  (If an allegation that the Governor's girlfriend could have improperly influenced certain negotiations was not sufficient I'm not sure what is.  Speaking of which, Governor Gibbons has also had some well publicized issues of his own.)

It could be that courts are deferential to executive privilege in these circumstances.  It could also be that they are turned off by a whiff of the political motivations underlying the requests (not that this is a valid reason to reject them).  Either way, even though public records statutes likely encompass email, it's easier said than done to get access from executives.  On the other hand, Governor Corzine had to have been scared off by the request.  According to news reports, he "swore off" email in reaction to the lawsuit.  (NYT) 

More on the experiences of some other governors and email from the Newsroom Law Blog ("New Year, New Governor, New E-mail Policies").