Alan Shapiro & Steven Wrappe (both of Deloitte) have published IRS Comments on Periodic Adjustments for Intangibles:  Looking for the Silver Lining, also available on the Tax Analysts web site as Doc 2005-6378, 2005 TNT 71-8.  Here is the Introduction:

In January 2005, the IRS for the first time in over 10 years provided public comments on the interpretation of the commensurate with income standard and the requirement to make periodic adjustments. The IRS apparently has been considering the need for further guidance in this area as part of the expanding project to propose amendments to the cost-sharing regulations. The comments, if included in regulations, could substantially limit a taxpayer’s ability to affirmatively use the commensurate with income standard and periodic adjustments in many situations. However, they could also provide welcome clarification of a taxpayer’s ability to shift risk without running afoul of the periodic adjustment rules.