It's good to have friends.
Wally McClure IM'ed me today to say that I gave some misleading information in my latest podcast on Architecting Ajax Applications. In the show I made mention to how Ajax will tax screen readers. Wally posted in December of 2005 about his experiences creating a working Ajax application for the blind and how he had success using Ajax with screen readers.
Part of what I was trying to get across in the show was that you can build anything incorrectly. As Wally points out Ajax doesn't have to propose a problem for you, but it's up to developers to build systems that will play nice with all users.
Thanks Wally!