New regs came out in August 2006:
www.ed.gov/policy/speced/guid/idea/idea2004.html
The Federal DOE's IDEA 2004 news page. A great place to start to the details of changes in IDEA since the 1997 version.

www.ed.gov/policy/speced/guid/idea/idea2004.html
US Department of Education (DOE) unofficial copy of the 2004 IDEA legislation. News and information, times and dates for public meetings, information on how to send comments. A copy of the proposed changs in the regulations is in the Federal Registry dated June 21, 2005. These are details but since this often mentions changes only, it is a little hard to follow without the old regulations in hand.

edworkforce.house.gov/issues/109th/education/idea/ideafaq.pdf
A downloadable set of Frequently Asked Questions from Mike Castle's Subcommittee on Education Reform that wrote IDEA 2004. A good summary but it includes some irrelevant (for the kids) chatter about what great guys the Republicans are for funding IDEA better than the Democrats.

www.nichcy.org/idea.htm
National Dissemination Center for Children with Disabilities. Text and PDF versions of the legislation, comments and eventually training materials on the changes.
 
www.copaa.org/news/idea04.html
Council of Parent Attorneys and Advocates. Lots of legal stuff including a detailed comparison of  the 1997 and 2004 versions of IDEA.
 
www.wrightslaw.com/idea
The Wrights Law page related to Idea 2004. Lots of information and comments and also includes this document describing the substantive changes to the five key statutes of IDEA 2004 by section and subsection. Text added to IDEA 2004 is in italics. Text deleted from IDEA 97 has been struck through.

www.cec.sped.org/pdfs/Initial_Summary.pdf
Council of Exceptional Children’s side-by-side comparison of IDEA 1997 and 2004 regs. Get it from the link above, or download it from our web site here. The CEC also has a copy of a doc from the Congressional Research Service at the Librabry of Congress: www.cec.sped.org/pp/docs/CRSAnalysisofNewIDEAPL108-446.pdf

www.ncld.org/advocacy/IDEA04_FAQ.cfm
National Center for Learning Disabilities IDEA 2004 FAQ on Changes to the Identification & Eligibility Procedures for Specific Learning Disability (SLD). Check out the IDEA Parent Guide that walks you through the major components of IDEA step-by-step.

www.taalliance.org/idea/factSheets.htm

Another page highlighting differences between new and old IDEA legislation from the Technical Assistance Alliance for Parents Centers.

www.c-c-d.org

The Consortium  of Citizens with Disabilities has a document outlining the changes brought by IDEA 2004. This one contains some history in addition to the changes. Download it here.