Glenn Greenwald has an interesting take on the Inspector Generals' Report  on Bush's Presidential Surveillance Program: 

The new Report on illegal spying is not a real investigation.

Glennwald writes:

...(1)  The IG Report is more notable for what it fails to address than for what it discloses, but that's the nature of IG Reports.  Most of the key players who authorized the illegal domestic spying -- David Addington, John Yoo, Dick Cheney, Andrew Card, John Ashcroft, George Tenet -- simply refused to talk to the IGs or, in many cases, didn't even bother responding to their request.  The IG's have no power at all to compel them to do so; it's entirely optional.  That -- aside from the fact that they work within the Executive Branch and for the very agencies they are supposed to investigate -- is what makes IGs such an inadequate substitute for real oversight:  no matter how much integrity and independence they might have, they are extremely limited in what they can achieve.  

As any litigator will tell you, the lack of power to compel key witnesses to answer questions and produce documents severely hampers any ability to conduct a real investigation.  Yet, when they passed the FISA Amendments Act -- which legalized Bush's spying programs and immunized lawbreaking telecoms -- Democratic leaders kept pointing to the requirement of an IG Report to placate those complaining that they were whitewashing and legalizing Bush abuses.  But IGs are simply incapable, given their very limited powers and their institutional allegiances, of any real investigation of this sort.  What they were unable to disclose in this Report underscores how limited are their investigative abilities...

Greenwald is correct - the IGs report is not a real investigation. Cheney, Addington, Yoo, Card, Tenet, Feith, and Ashcroft did not cooperate with the inquiry. It's obvious that Executive Branch with its "look-forward with head stuck in dirt" mentality - adopted/enforced by Holder's DoJ - does not plan to investigate Bush's PSP. It's was Congressional dereliction of duty - gross negligence of Constitutionally-mandated oversight by both Republicans and Democrats - that permitted and enabled the lawlessness of the Bush administration. Congress has all the ammo it needs right now to launch a kick-ass investigation replete with subpoenas, contempt citations, and prosecution and imprisonment to those who think non-cooperation is an option. Congressional Republicans and the neocons will scream their heads off accusing the Democrats of "witch hunts" and endangering national security. The Democrats need to do this in order to rehabilitate itself and recover from its decade long self-castration.