According to the May 30 Tax Notes Magazine, Eric Solomon, the acting Treasury Deputy Assistant Secretary for Tax Policy, suggests that Congress, with respect to anti-tax shelter legislation, "take a moment, take a breath, and take a look at what has happened, what is going on, and what the effect is of the legislation and the enforcement initiatives." In other words, no more legislating in the area, please, for now.
Solomon, a truly public-spirited public servant (under both Clinton and Bush, no less) whom I greatly admire, has a point. Congress has a way, when an issue is on the public agenda, of passing a flurry of responses without much overall deliberation or coordination.
The one disagreement I have with Solomon on this concerns the idea of putting the economic substance/business purpose requirement for tax shelters in the Internal Revenue Code, rather than having it just be case law. This is a problematic issue, and both the Treasury and tax practitioners have tended to oppose doing this. One reason I think it is nonetheless a good idea is that several court decisions recently have suggested a lack of understanding or acceptance of the requirement, and indeed I am told that a couple of recent decisions have cited Congress's non-enactment of the statutory rule as indicating that they shouldn't rely on it. (This is bad statutory interpretation, by the way, since non-enactment both need not indicate dislike of the requirement and is not a legislative act.)
Note, moreover, that Justice Scalia's increasingly influential "textual" and anti-purposive approach to statutory interpretation suggests that the Supreme Court might throw out the economic substance line of cases at some point if there is no hook in the Internal Revenue Code indicating that Congress wants it to stay.