There is quite a bit of stuff out there.
Here is the page with comments to the ARC:
http://dms.dot.gov/search/searchResu...rchType=docket
Here are some FAA studies:
http://www.faa.gov/library/reports/medical/age60/
Here are a couple of pro-change websites:
http://www.apaad.org/
http://www.ppf.org
http://www.age60rule.com
Here are a lot of historic documents; I suggest reading all of them:
http://www.age60rule.com/history_frameset.html
That's a start.