President Bush issued one of his infamous "signing statements" for HR 199 - the "USA PATRIOT Improvement and Reauthorization Act of 2005". In it, he seems to say that he will ignore reporting provisions specifically laid out by his own party.
Orin Kerr sums it up at The Volokh Conspiracy.
Some influential lawyers in the Administration believe that Congress has only limited ability to interfere with the executive branch, and such statements express the Administration's intent not to follow provisions that its lawyers believe interfere with executive power. In most cases, we don't know what the statements mean: the executive branch announces that it is taking a position based on its view of Article II, but never discloses exactly what that position is.
Congress has required DOJ to conduct audits and file reports, and we'll presumably learn the executive branch's view of the law when it refuses to comply in whole or in part with Congress's requirements.
One of the most troubling qualifications, I think, is this:
The executive branch shall construe the provisions...in a manner consistent with the President's constitutional authority to supervise the unitary executive branch and to withhold information the disclosure of which could impair foreign relations, national security, the deliberative processes of the Executive, or the performance of the Executive's constitutional duties. *
Think of what all that implies - impair foreign relations? the deliberative processes of the Executive? I think this is another invocation of the new anti-embarrassment legal principle. Of course, as Kerr rightly notes, we won't know until it happens. If there's one thing we're never going to get from this administration, it's a straight answer.
On a lighter note, I think it would be great if there was a Constitutional requirement that the President explain, in his own words, what his statements mean.
* Emphasis mine.