IRS regulation of nonprofits

Steven Miller, IRS Director of Tax Exempt and Government Entities, gave a speech recently on nonprofits. As the Nonprofit Law Prof blog reports, the most provocative part of the speech:

Please understand that I am not saying that no valid differences exist between the non-profit and for-profit sectors. I am asking something more nuanced: to what degree has the non-profit sector drifted toward the commercial sector, and to what extent should it be taxed like the for-profit sector? And even where the exempt sector acknowledges unrelated commercial activity, why are so many organizations declaring losses on these endeavors? It seems as if the IRS needs to police this Drift Line.

Newcomers to the nonprofit world are often surprised to the extent nonprofits (particularly 501(c)(3)s) are able to engage in commercial-like activities. Will the IRS start taking a harder line?