Whether Scooter Libby did or did not do the things he's accused of in the indictment is not relevant to the central political/ethical issues arising from the Plame affair.
That's not to say that the indictment isn't important in its own right. Certainly, it's a serious matter for Libby personally. He's entitled to the presumption of innocence and to all the protections that our criminal procedure affords. And some of the questions that have been batted around by the talking heads are interesting: how serious are perjury and obstruction of justice in general? given that it occurs much more often than it is prosecuted, what factors should drive a prosecutor's determination of whether to charge someone with perjury in a particular instance? was this a reasonable case in which to seek such an indictment? is what Libby is accused of having done more or less serious that what Clinton was accused of? and so forth.
But these questions have very little, if anything, to do with the Plame affair generally. The central point there, which seems to be less and less deniable, is that the administration retaliated against or tried to undermine the credibility of a critic by releasing classified information about his wife. It's made worse by the fact that the criticism was in the form of apparently truthful information about the administration's knowledge regarding Saddam's supposedly reconstituted nuclear program and that the classified information was the identification of a CIA agent.
These acts may or may not be crimes in themselves, and Fitzgerald hasn't foreclosed the possibility that someone will be indicted for them. But whether or not there is an indictment, the scandalous and reprehensible nature of the administration's conduct will not change. If the law does not criminalize the actions of any particular individual in the matter, or if the prosecutor can't prove beyond a reasonable doubt what he needs to prove, or if for some other reason he or the grand jury do not see fit to bring charges, that does not validate the outrageous attack launched two years ago by the closest of the president's inner circle.
The same is true, even more so, of the Libby indictment. If he's convicted, that won't make what was done in 2003 any more reprehensible. And if he's acquitted, it won't justify those events either.