The 10th Circuit has entered an order denying rehearing and rehearing en banc in the Spending Clause challenge against Section 1926(b) protection in the Guthrie litigation.
For a description of the petition for rehearing, click here: http://www.oklahomawaterlaw.com/2011/09/petition-for-rehearing-filed-in.html
The petition for rehearing can be found here: http://www.jdsupra.com/post/documentViewer.aspx?fid=62112eb7-fc7b-4c2b-ad97-843d2dfb1593
The 10th Circuit's 7/25/2011 ruling is described here: http://www.oklahomawaterlaw.com/2011/09/tenth-circuit-decision-in-guthrie-could.html
The 7/25/2011 opinion is found here: http://www.ca10.uscourts.gov/opinions/08/08-6003.pdf
This development could end the challenge that has been in litigation for a number of years. See, e.g.: http://www.oklahomawaterlaw.com/2005/10/rural-water-districts-in-oklahoma-lack.html